Peruvian expeditions, 1911-1915-
Publications no. 39.

I

YALE UNIVERSITY
LIBRARY

1922

REPOfcf ON ?m MAMMALIA ClOttECCED BY MR.
EDMUND HELLER DURING THE PERUVIAN EXPE
DITION OF 1915 UNDER THE AUSPICES OF
YALE UNIVERSITY AND THE NATIONAL
GEOGRAPHIC SOCIETY V4LE "0/-.

BT

OLDFIELD THOMAS
Of A* Britbh Muwvn, Loadwi, Eoftaui

No. 2333.— Prom the Proceedings of the United States National Museum
Vol. 58, pages 217-249, with Plates 14-15

Washington
Government Printing Office
1920 <

REPORT ON THE MAMMALIA COLLECTED BY MR.
EDMUND HELLER DURING THE PERUVIAN EXPE
DITION OF 1915 UNDER THE AUSPICES OF
YALE UNIVERSITY AND THE NATIONAL
GEOGRAPHIC SOCIETY

BY

OLDFIELD THOMAS
Of the British Museum, London, England

No. 2333. — From the Proceedings of the United States^National Museum
Vol. 58, pages 217-249, with Plates]14-15

Washington
Government Printing Office
1920

REPORT ON THE MAMMALIA COLLECTED BY MR. ED
MUND HELLER DURING THE PERUVIAN EXPEDITION
OF 1915 UNDER THE AUSPICES OF YALE UNIVERSITY
AND THE NATIONAL GEOGRAPHIC SOCIETY.

By Oldfiedd Thomas,
Of the British Museum, London, England.

In 1912 and succeeding years an expedition was organized under
the auspices of Yale University and the American National Geo
graphic Society for the exploration of the deserted Inca city Machu
Picchu, in the Cuzco region of Peru. To the 1915 staff of the expedi
tion there was attached, as zoological collector, Mr. Edmund Heller,
already so well known for his work in California and British East
Africa, and it is on the result of his labors round Machu Picchu
that the following paper is based. The collection has been placed in
my hands by the authorities of the United States National Museum,
at the kind suggestion of Mr. Gerrit S. Miller.1 Thanks to my inter
est for many years in the.mammal fauna of the region, its examina
tion has been a very great pleasure to me, and I must express my
acknowledgments to those to whom I owe the privilege of working
it out.
An account of Machu Picchu and the highly successful expedition
of 1912 for its discovery and exploration is given by Prof. Hiram
1 The Peruvian mammals were sent to Mr. Thomas in July and Decemher, 1916, a time
when the German submarine campaign made transportation sufficiently dangerous to war
rant the retaining of a reserve series in Washington. With the assistance of Mr. N.
Hollister I therefore divided the collection into two parts, one of which was to be for
warded to London and the other to be kept here. Our syatem in picking out the two sets
waa as follows: The various groups were divided into as many forms as appeared to be
obviously or possibly diatinct. Of each of these forms at least one specimen from every
locality represented was placed in the first set. Moderately large series were divided
about evenly between the two, but in the case of very extensive series the first set re
ceived not more than a representative lot of specimens. The material which forms the basis
of this paper, though it numbers only 614 specimens out of a total of 892, is supposed
to represent every mammal obtained by Mr. Heller. While it is unfortunate that it was
necessary to divide the collection in this way, there ia little probability that any forma
not included in the first set were retained in the second. At the time of making the division
we thought that the entire number represented by the material sent to London was
slightly above 70 ; but only 65 were identified by Mr. Thomas. The lists of specimens
here published are limited to the first set. The photographs reproduced in plates 14 and
15 show the skulls of all of the type specimens in the collection. They were made
under my supervision after the material had been returned. — G. S. M., jr.

Proceedings U. S. National Museum, Vol. 58-No. 2333. 217

218 ' PROCEEDINGS OF THE NATIONAL MUSEUM. vol.58.
Bingham in the National Geographic Magazine,1 with illustrations
which show well the physical characters, the mighty mountains, and
stupendous river valleys of the region where the collection was made.
Machu Picchu is itself on the Urubamba River, some 45 miles north
west of Cuzco ; and while it was being explored by the archaeologists
of the party, Mr. Heller made collecting trips in different directions
from it, so that the area over which the mammal collection was
made extends from the Rio Comberciato, about 65 miles northwest of
Machu Picchu to Pucara, close to Cuzco, all the places being in
the drainage system of the Urubamba. A small number of speci
mens were also got at La Raya Pass, 100 miles southeast of Cuzco,
on the watershed dividing the upper Urubamba from the Upper
Pucara, which runs southeastward to Lake Titicaca. The exact
positions of most of the localities are shown in Professor Bingham's
map. Considering its remoteness from civilized regions and the immense
difficulties involved in making collections in such a place, it is cer
tain that only a large and well-equipped expedition, such as that
under the direction of Professor Bingham, could have provided an
opportunity for a collector to have obtained anything like a complete
series of the mammals of this area.
The collection consists of nearly a thousand specimens of all orders,
but it is chiefly rich in Muridae, which Mr. Heller was extremely
successful in capturing. In all it contains 65 species, of which I have
found it necessary to describe 12 as new. Short diagnoses of all but
one of these have been already published.2 Of the novelties, by far
the most interesting is a new Marsupial nearly related to Coenolestes,
but sufficiently distinct to be regarded as a different genus. Members
of the family were previously known from Colombia and Ecuador, so
that the present is a considerable extension of the recent range of
the group.
Within the area now dealt with, of which the crossing of 13° S.
with 72° 30' W. may be taken as the center, almost no collections of
mammals have been made, a couple of small series sent to the British
Museum by O. Garlepp in 1898 and 1903, and a few odd specimens,
also in the British Museum, obtained by the Polish collector J. Kali
nowski, appearing to be all that are recorded, although there may
be a few others which I do not know of. In order to make the pres
ent list as complete as possible I have included in it the specimens of
the Garlepp and Kalinowski collections, so that it contains all the
species as yet known from the area. Near-by regions are, however,
more richly represented, notably the district of Junin, where both
1 In the Wonderland of Peru, by Hiram Bingham, Nat. Geogr. Mag., vol. 24, p. 387
April, 1913.
2 Smithsonian Miscel. Coll., vol. 68, No. 4, April 10, 1917.

no. 2333. MAMMALIA COLLECTED IN PERU BY HELLER— THOMAS. 219
Jelski and Kalinowski worked, and localities on the Rio Perene and
Rio Inambari, where that fine collector, P. O. Simons, secured for
us the first Peruvian series ever made in modern fashion. The last
named also went to many other localities in P'eru and Bolivia,, and
the majority of the species I have described were discovered by him.
The only other modern Peruvian collection of importance is that
recently made in the northwest by Messrs. Osgood and Anderson,
and worked out by the former in 1913 and 1914. None of these col
lections, however, is anything like so complete a representative of its
locality as the present one, which probably surpasses any other ever
made in South America. Mr. Simons moved about too much to have
worked any one locality as well ; Messrs. Osgood and Anderson were
merely passing through ; while no one else of equally trained ability
has entered the country.
The following is a list of f aunal publications relating to the mam
mals of Peru, but of course much if not most of the literature is in
the form of scattered observations on the different animals :
1844-1846. Tschudi, J. J. von. Fauna Peruana. Mammalia, pp. 1-262. In
an effort to make it appear complete the accounts of the species in this work
have been made so generalized as to deprive them of much of their value.
This is notably the case with the geographical distributions, which even in
the case of rare species are usually in quite general terms, without mention of
particular localities.
1882. Thomas, O. On a collection of Eodents from N. Peru. [Coll. J. Stolz-
mann.] Proc. Zool. Soc. London, 1882, p. 98. Turnbez, Cajamarca, etc.
1884.  . On a collection of Muridae from Central Peru. [Coll. C.
Jelski.] Proc. Zool. Soc. London, 1884, p. 447. Junin region.
1893.  On some mammals from Central Peru. [Coll. J. Kalinowski.]
Proc. Zool. Soc. London, 1893, p. 333. Chanchamayo and neighborhood.
1897. Allen, J. A. On a small collection of Mammals from Peru. [Coll.
O. T. Baron.] Bull. Amer. Mus. Nat. Hist, vol. 9, p. 115, 1897. Cajabamba,
North Peru, and neighborhood.
1899. Thomas, O. On some small mammals from the district of Cuzco, Peru.
[Coll. O. Garlepp.] Ann. and Mag. Nat. Hist., ser. 7, vol. 3, p. 40, 1899.
1900. Allen, J. A. On Mammals collected in Southeastern Peru by Mr. H. H.
Keays. Bull. Amer. Mus. Nat. Hist., vol. 13, p. 219, 1900. Inambari Kiver.
1901. Thomas, O. New Mammals from Peru and Bolivia, with a list of those
recorded from the Inambari River. [Coll. P. O. Simons and others.] Ann. and
Mag. Nat. Hist., ser. 7, vol. 7, p. 178, 1901.
1902.  . On Mammals from Cochabamba, Bolivia, and the region
north of that place. [Coll. P. O. Simons]. Ann. and Mag. Nat. Hist., ser. 7,
vol. 9, p. 125, 1902. Many of these Bolivian species range into the Cuzco
region. 1913. Osgood, W. H. New Peruvian Mammals. [Coll. W. H. Osgood and M.
P. Anderson]. Field Mus. Nat. Hist. Publ., vol. 10, p. 95, 1913. Moyobamba,
Cajamarca, etc.
X914.  . Mammals of an Expedition across North Peru. Field
Mus. Nat. Hist. Publ., vol. 10, p. 145, 1914. Moyobamba route.
1916  . Mammals of the Collins-Day South American Expedition.
[Coll. G. K. Cherrie and R. H. Becker]. Field Mus. Nat. Hist. Publ., vol. 10,

220 PROCEEDINGS OE THE NATIONAL MUSEUM. V0L- 58,
p. 199, 1916. Mostly relating to Bolivia and the Amazons, but a few speci
mens recorded from the Peruvian plateau.
No specimens were obtained by Mr. Heller of the two rodents de
scribed by Mr. Eaton, the osteologist of the party, on skulls found by
him in the Inca tombs of Machu Picchu during the 1912 expedition,
Aorocoma oblativa and Agouti tkomasi;1 nor of Lagostmnus crassus
described by myself in 1910 2 on a skull found in the sand at Santa
Ana by Mr. Kalinowski. The first and third of these animals are in
all probability now completely extinct, judging by the fact that their
relatives are no longer found in this f aunal area, but only far south
in Chile and Argentina. On the other hand, the second species,
which is closely allied to living Andean forms, will perhaps be found
still to exist in the neighborhood.
Finally, I must express by acknowledgements to Miss Winifred
Davidson for the assistance she has given me in sorting, handling,
and labeling the large series of specimens, an assistance which has
materially eased the labor of preparing the present report.
1. ATELES ATER F. Cuvier.
Adult and young*female, Nos. 194337 and 194339, Rio Comberciato
(3,000' feet).
An adult specimen in the British Museum from Pachitea, deter
mined by Doctor Eliot, is very similar to these.
2. AL.OUATTA SENICUL.US Linnaeus.
Three males and one female, Nos. 194349, 194352, 194353, and
194354, Rio Comberciato (2,000-3,000 feet) .
3. CEBUS UNICOLOR CUSCINUS Thomas.
Male and female, Nos. 194356 and 194357, Uvirii, Rio Cosireni
(5,000 feet).
[Female, No. 98.11.6.1, B. M., Callanga, Cuzco. O. Garlepp.
These two specimens of the Cuzco Geius agree in every detail with
the type and confirm its distinction as a local form. I accept for
the moment its relation with unicolor, as advocated by Doctor
Elliot, who appeared doubtful of its validity, owing to its being
based on a single example. Mr. Heller's specimens are therefore
of interest as tending to resolve the doubt in the matter.
The greatest skull length of the male (not fully adult) is 95 mm.;
of the female (old) , 90 mm.
1 Mem. Conn. Acad., vol. 5, p. 87, 1916.
2 Ann. and Mag. Nat. Hist, ser. 8, vol. 5, p. 246, 1910.

xo. 2333. MAMMALIA COLLECTED IN PERU BY HELLER— THOMAS. 221
[CEBUS AZARAE PALLIDUS Gray.]
[Three males and one female, Nos. 97.10.3.4-7, B. M., Idma, Santa
Ana, Cuzco. J. Kalinowski.]
The association with azarae is accepted on the a uthority of Doctor
Elliot.1 I had already referred the specimens to Gray's palKdus.
4. LAGOTHRIX THOMASI Elliot.
Young male, No. 194343, Rio Comberciato (2,000 feet).
[Female, No. 98.11.6.2, B. M., Callanga, Cuzco (5,000 feet). O.
Garlepp. Type.]
No. 194343 of the present collection is quite young, so that it can
not be determined with any certainty. It may perhaps be referable
to the Cuzco form described by Doctor Elliot as L. thomasi.
*
5. SAIMIRI BOLIVIENSIS NIGRICEPS Thomas.
Three males and one female, Nos. 194344-7, Rio Comberciato (2,000
feet) .
These specimens, and others recently received, confirm Doctor
Elliot's observation that nigriceps may be distinguished from ooli-
viensis by the deeper and more golden orange color of the forearms
and feet, the tone in boMviensis being more yellowish. On the other
hand, the intensity of the blackness of the cap, on which I primarily
distinguished the subspecies, proves to be subject to considerable
change with age, the older specimens having this a deeper black than
the younger. Besides the type from Cosnipata, examples of nigri
ceps are in the British Museum collection from Marcapata (Kalinow
ski) and Tahua Manu River (Maj. H. S. Toppin).
6. LE0NT0CEBTJS PURILIAJS Thomas.
Four specimens as follows :
Rio Cosireni, 3,000 feet, male and female, Nos. 194331, 194334.
Rio San Miguel, 4,500 feet, male and female, Nos. 194335-6.
These four specimens agree remarkably well with the type of L.
purilhts, which came from the Acre River, Upper Purus River, some
200 miles northeast of the present locality.
In the description, which was based on a single specimen that had
been in confinement, emphasis was laid on the amount of ferruginous
at the base of the tail, and on the buffy suffusion. of the dorsal mar
bling ; but both these characters prove to be variable on the evidence
of Mr. Heller's specimens. On the other hand, the latter show one
very well marked characteristic of the species which was not readily
perceptible on the menagerie-soiled type — namely the white V-shaped
frontal patch, extending the white of the muzzle backwards on each
1 Primates, vol. 2, p. 108.

222 PROCEEDINGS OF THE NATIONAL MUSEUM. YOh- oS;
side over the eyes, a little" suggesting the V-shaped eyebrows of the a
conventional pictures of Mephistopheles, done in white instead of
black [MYOTIS NIGRICANS Wied.]
Six specimens in the British Museum, as follows :
Santa Ana, Nos. 97.10.3.20-21. J'. Kalinowski.
Callanga, Cuzco, Nos. 98.11.6,3-5. O. Garlepp.
Marcapata, Cuzo, No. 3.2.9.1. O. Garlepp.
7. PEROPTERYX CANINA Wied.
One specimen in alcohol, Machu Picchu, No. 195118, is too much
damaged for certain determination.
8. MOLOSSUS OBSCURUS Geoffroy.
Two specimens in alcohol, Santa Ana, Nos. 195173-4.
9. TADARIDA BRASILIENSIS Geoffroy.
Thirty-two specimens, as follows :
Machu Picchu, 6,000 feet, 3 (Nos. 194440-2).
Santa Ana, 3,500 feet, 29 (Nos. 194443-8, also 23 in alcohol not
individually listed). Taken under tiles of roof.
10. GLOSSOPHAGA SORICINA Pallas.
Three specimens, as follows :
Santa Ana, 1 (No. 195125, in alcohol).
Idma, 6,000 feet, 2 (Nos. 194455 and 195126). No. 194455 was
taken inside of a house. It contained one embryo.
11. ANOURA GEOFFROYI Gray.
Male, No. 195127, Ollantaytambo.
Represents Tschudi's Ghoeronycteris peruana.
12. PHYLLOSTOMUS HASTATUS Pallas.
Five specimens from Comberciato, 1,800 feet (Nos. 194460-4).
13. HEMIDERMA CASTANEUM H. Allen.
Seven specimens from Idma, 6,000 feet (Nos. 194436-9, also three
in alcohol).
Quite similar to specimens obtained in Ecuador by G. Hammond,
submitted to Mr. Gerrit Miller, by whom they were pronounced to be
identical with H. castaneum, and compared with the common H.
perspicillatvm. The species is distinguished both by its smaller skull and by the
smaller size of the teeth, which are, however, remarkably variable,
scarcely any two of the specimens agreeing in all details of the
dentition.

no. 2333. MAMMALIA COLLECTED IN PERU BY HELLER— THOMAS. 223
No. 194438 is also anomalous in having its two upper posterior
molars represented by a single one only, this being approximately of
the shape of the normal last molar.
[STURNIRA LILIUM Geoffroy.]
[One specimen in the British Museum from Ocobamba, Cuzco. No.
98.11.6.6. O. Garlepp.J 14. DESMODUS ROTUNDUS Geoffroy.
Eleven specimens from Puquiura, 9,500 feet. (Nos. 194456-9 ; also
seven in alcohol.) 15. FELIS PUMA Molina.
Male, No. 194310, Piscocucho, 8,700 feet. Condylobasal length of
skull, 192 mm. 16. FELIS PARDALIS Linnaeus.
Male, No. 194311, Santa Ana.
17. PSEUDALOPEX CULPAEUS ANDINA Thomas.
Two specimens, as follows :
Paccaritampu, 1 (male, No. 194312).
Ocobamba Valley, 1 (male, No. 194313).
The Ocobamba specimen is a fine example in full winter pelage
and agrees in all respects with the typical series. That from Paccar
itampu is in poorer fur, and is rather smaller than usual. The skulls
measure 159 and 148 mm. in condylobasal length, respectively.
18. POTOS FLAVUS Schreber.
Female, No. 194317, Uvini, Cosireni River (4,000 feet). Stomach
contained figs.
This is the most southern locality from which the Kinkajou has
been obtained, the nearest to it being Pozuzo, whence a pair is now
in the British Museum. The specimen has a well-marked dorsal
streak, and its skull measures 77.5 mm. in condylobasal length.
19. BASSARICYON ALLENI Thomas.
Adult and young female, Nos. 194315 and 194316, Rio Cosireni
(3,000 feet). Stomach contained fruit and green vegetable pulp.
Except that the skull of the adult is slightly larger (condylobasal
length, 79.5 mm.) these specimens agree absolutely with the Ecua
dorian and Peruvian examples of B. alleni in the British Museum,
having the same fulvous color, grayish face, and flattened frontal
region of the skull.
The localities now represented for the species are Sarayacu and
Gualaquiza, Ecuador (Buckley and Hammond), Pozuzo, Chancha-
mayo, and Rio Cosireni, Peru, (Egg, Schunke, and Heller) .

224 PROCEEDINGS OF THE NATIONAL MUSEUM.  T0L- 58,
A Bassaricyon from Munduapo, on the Orinoco, collected by J- K.
Cherrie, appears to be referable to B. medius Thomas.
20. MUSTELA AUREOVENTRIS Gray.
Three specimens from Ollantaytambo, 9,000 feet (male No. 194326,
female No. 194327 and an unsexed specimen, No. 194328) .
[Male from Ocobamba, Cuzco, No. 98.11.6.1, B. M., O. Garlepp.]
Following Doctor Allen 1 1 accept the identity of this dark-headed,
yellow-bellied stoat with the species from Ecuador and Northern
Peru, for which he uses Taczanowski's name macrura. But whether
it is really distinct from the white or gray -bellied M. agilis of Tschudi
appears to me doubtful in view of the considerable variability in
color found in this group. An example from Lima, sent to England
by the late Professor Nation, which I provisionally refer to Tschudi's
species, has a practically white under surface and well-marked facial
hands. The name aureoventvis is not invalidated by the earlier awiventer
of Hodgson, as, apart from " one-letterist " differences, its first half
comes from the adjective aureus, while Hodgson's name is based on
the substantive aurum, so that not only the spellings but the deriva
tions are different. 21. CONEPATUS AREQUIPAE Thomas.
Seven specimens, as follows :
Chospyoc, two males (Nos. 194321-2).
Urea, near Calca, female (No. 194324).
Machu Picchu, male (No. 194323).
Ocobamba Valley, two males (Nos. 194318-9) and one female (No.
194320). These specimens confirm what I said in 1902 as to the difficulty of a
proper determination of the members of Gonepatus, and the proba
bility that most of the forms would be found to grade into each other.
Specimens from any given region have a generally similar facies, but
almost every character varies individually, so that a diagnosis which
shall cover every example is almost an impossibility. The present se
ries all agree in having a long coarse coat and very brOad white
stripes, which are connected on the crown, the first character dis
tinguishing them from G. sorrino and the second from G. inca. But
in the reversal or nonreversal of the nape hairs, the separation or par
tial junction of the white stripes on the withers and the extension of
the stripes down the back, there is considerable variation among
them. In two out of the three Ocobamba Valley specimens the stripes
even reach to the base of the tail, a character which I had hitherto

1 Bull. Amer. Mus. Nat. Hist., vol. 35, p. 101, 1916.

no. 2333. MAMMALIA COLLECTED IN PERU BY HELLER— THOMAS. 225
believed to be one of those that distinguished the Chilean skunk,
G. chinga, from all the forms of Peru and Bolivia.
With regard to nomenclature all may for the present bear the name
G. arequipae, the type of which falls obviously into the same series,
while G. chorensis (now that we know that the direction of the nape
hairs is not a trustworthy character) and G. porcinus (if any mistake
has been made as to the sexing of the type) may have to be united
with the same animal. But the male skull of G. chorensis is a little
smaller than that of arequipae.
The largest male skull of the present series, No. 194319, measures
83.2 mm. in condylobasal length.
22. LUTRA EMERITA Thomas (or COLOMBIANA Allen).
Female, No. 194325, Rio Comberciato (2,000 feet). Contained two
small embryos.
Allowing for the sexual difference in the size of the skull, this
specimen agrees remarkably well, especially in the shape of its nose
pad, with the type of L. emerita, which may, however, prove to be
synonymous with Allen's L. colombiana, a species I overlooked when
writing my notes on South American otters in 1908.1 The species
would therefore seem to range all the way down the Andean chain
on its eastern slope.
On the other hand, from quite near the present locality, the two
examples of L. incarum, Thomas, as explained in the original de
scription, both show the form of the nose pad found in L. platensis,
so that we have here otters with both types of nose pad occurring in
the same locality. Whether the value of the character needs revision
only much further material will show.
Another otter with the emerita type of nose pad is the South
Chilian L. provocax, whose northward extension we do not yet
know. There has been some doubt about the name of this animal,
as it is" certainly the species called Lutra huidobria by Gray and
others, who based their use of the name on Molina's " Castor hmdo-
triusP But I am not prepared to recognize as an otter a species
described as having long rodent incisors and unpalmated forefeet,
and think that in view of the insoluble mixture of local names,
habits, and characters contained in Molina's description the name
Castor huidobrius should be set aside as indeterminable.

'After its return from London I submitted this otter to Dr. J. A. Allen for com
parison with Lutra colombiana. He writes as follows (Dec. 5, 1919) : " I have care
fully compared the skin and skull of the otter from Peru with the type and two other
specimens of my Lutra ¦colombiana. There are no appreciable external differences, but
the skull is slightly larger and more heavily built, with noticeably stouter teeth ; also the
pterygoid fossa is slightly longer and narrower. The Peruvian form should probably
be considered as suhspecifically separable from colombiana. The specimens I have been
able to compare are all females and of about the same age as the Peruvian specimen." —
G. S. M., jr.
181404 — 20 — Proc.N.M.vol.58  15

226 PROCEEDINGS OF THE NATIONAL MUSEUM. vox" 5S'
23. TREMARCTOS ORNATUS F. Cuvier.
Female, No. 194309, Machu Picchu.
The skull of this bear corresponds closely with those from Cos-
nipata, Inambari, which I used for comparison in giving a name to
the Ecuador T. o. majori. It is 191 mm. in condylobasal length by
128 mm. in zygomatic breadth. The two upper molars together
measure 37 mm.
The skin presents a good example of the uselessness of the " spec
tacles " as a distinctive character, for it has a light supraorbital line
on one side and not on the other.
24. SCIURUS CASTUS Thomas.
Female, No. 194486, Rio Comberciato (2,000 feet).
25. SCIURUS CUSCINUS Thomas.
Female, No. 194487, Rio Comberciato (2,000 feet).
Two females from San Fernando; Rio San Miguel, 4,000 feet
(Nos. 194488-9).
[Two, Nos. 98.11.6.8-9., B. M. (No. 8 the type), from Ocobamba.
O. Garlepp.]
[Three, Nos. 3.2.9.3-5., from Marcapata. O. Garlepp.]
26. MUS MUSCULUS Linnaeus.
Eleven specimens, as follows:
Huaracondo, Cuzco, 2 (Nos. 194502-194765).
Chospyoc, 10,000 feet, 2 (Nos. 194503, 194905).
Ollantaytambo, 9,400 feet, 5 (Nos. 194504-5, 194508-10),
Idma, 6,000 feet, 2 (Nos. 194513-4).
HOLOCHILUS INCARUM, new species.
A medium-sized species related to H. sciureus, but less buffy on
flanks. Size apparently about as in II . sciureus, but no adult female avail
able for examination. General color above umber brown, not
markedly more buffy on the flanks. Under surface slaty, washed
with buffy, the hairs on a small patch on the throat white to their
roots, but everywhere else broadly slaty at base, cinnamon buff termi
nally. Ears small, hairy, not darker than the general color of the
head. Upper surface of hands and feet, buffy whitish. Tail about
the length'of the head and body, thinly haired, brown, rather lighter
at base below.
Skull (pi. 14, fig. 1) not heavily ridged, but the only skull avail
able is immature. Teeth comparatively small, as is usual in the
Amazonian forms of HolocMlus.
Dimensions of type, measured in the flesh by Mr. Erdis :

no. 2333. MAMMALIA COLLECTED IN PERU BY HELLER— THOMAS. 227
Head and body, 128; tail, 132; hindfoot (with claws), 36 (34 with
out claws on the dried skin) . The hindfoot of No. 194917 measures
36 mm. (without claws) , dried. Skull of type (immature) ; greatest
length, 34 ; condylo-incisive length, 31 ; nasals, 14 ; palatilar length,
29 ; palatal foramina, 6.2 ; upper molar series, 7.2.
Type. — Immature female, from Santa Ana, U.S.N.M. No. 194915.
Original No. 581. Collected December 22, 1914, by E. C. Erdis.
Specimens examined. — Male and two females from Santa Ana,
3,480 feet (Nos. 194917, 194915, 194919).
While a half -grown HolocMlus from the Ucayali at the mouth of
the Pachitea (alt. 440 feet), collected by Garlepp in 1903, is so ex
actly like equally immature specimens of H. sciureus that I see no
reason to distinguish it, these specimens, from altitudes over 3,000
feet, are so uniformly without the marked wash of buffy on "the
flanks characteristic of that animal that they should apparently have
a special name.
Unfortunately the material is somewhat imperfect, as neither
194917 nor 194919 has a skull, while the type is decidedly immature.
The Pachitea specimen, like those of the lower Amazon, has a well-
marked buffy wash along the flanks, and it is not improbable that
from Peru, at a comparatively low altitude, right down the Amazon
to Para and Pernambuco, only one species of the genus is found, a
distribution not impossible in so water-loving an animal. I confess
now to considerable doubt as to whether H. guiamae ought to have
been separated from H. sciureus — a doubt which also applies to
H. amazonicus.
The N. Peruvian HolocMlus obtained by Mr. Osgood in 1912, also
immature, is presumably the same as that from Pachitea.
27. NECTOMYS GARLEPPI Thomas.
Fifteen specimens, as follows:
Rio Comberciato, 2,100 feet, 1 (No. 194830).
Rio Cosireni, 3,000 feet, 1 (No. 194831).
Rio San Miguel, 4,500 feet, 3 (Nos. 194832, 194834-5).
Santa Ana, 6 skins (Nos. 194906-11) and 4 in alcohol (Nos. 195111-
14). The single adult specimen of this series, No. 194830, is somewhat
intermediate between N. garleppi and the North Peruvian iV. apicalis
Peters. I provisionally apply to it the name which is geographically
most pertinent. 28. ORYZOMYS KEAYSI Allen.
Thirteen specimens, as follows:
Machu Picchu, 6,000 feet, 11 (Nos. 194550, 194553, 194556, 194558-
60, 194562-3, 195108~9).
Paltaybamba, 5,000 feet, 1 (No. 194883).
Santa Ana, 3,480 feet 1 (No. 195093).

228 PROCEEDINGS OF THE NATIONAL MUSEUM. V0L- 5S'

29. ORYZOMYS NITIDUS Thomas.

Thirteen specimens as follows:
Machu Picchu, 6,000 feet, 4 (Nos. 194549, 194881-2, 194899).
Rio Cosireni, 3,000 feet, 1 (No. 194829).
Rio Comberciato, 5 (Nos. 194885-6, 194888-90).
Rio San Miguel, 4,500 feet, 2 (Nos. 194564-5).
Santa Ana, 3,500 feet, 1 (No. 194587).
30. ORYZOMYS STOLZMANNI Thomas.
Forty-three specimens, as follows :
Huaracondo, 11,000 feet, 1 (No. 194840).
Chospyoc, 10,000 feet, 5 (Nos. 194842-5, 194119).
Torontoy, 8,000-10,000 feet, 3 (Nos. 194842, 194847-8).
Machu Picchu, 6,000-8,000 feet, 9 (Nos. 194804-5, 194849-50,
194861, 194864, 194900-1, 195107).
Ollantaytambo, 13,000 feet, 3 (Nos. 194806, 194851-2).
Ocobamba Valley, Tocopoqueyu, 9,100 feet, 1 (No. 194853).
Paltaybamba, 5,000 feet, 1 (No. 194880).
Lucma, 9,000 feet, 2 (Nos. 194865, 194891).
Rio Cosireni, 3,000 feet, 1 (No. 194884).
San Fernando, 4,500 feet, 4 (Nos. 194854-5, 194892-3).
Idma, 6,000 feet, 5 (Nos. 194856, 194858-9, 195105-6).
Huadquifia, 5,000 feet, 1 (No. 194860).
La Raya Pass, 14,000 feet, 3 (Nos. 194783, 194903-4).
[Ocobamba and Callanga, Cuzco, 3 (B. M. Nos. 99.10.6.7 and 9,
98.11.6.23). O. Garlepp.]
[Marcapata, Cuzco, 1 (B. M. No. 13.2.3.12). O. Garlepp.]
31. ORYZOMYS (MICRORYZOMYS) AURILLUS Thomas.
1917. Oryzomys (Microryzomys) aurillus Thomas, Smiths. Misc. Coll.,
vol. 68, No. 4, p. 1. April 10, 1917.
General color about as in O. minutus, much less strongly buffy than
in O. dryas; ears longer than in either.
Fur soft, close, and woolly, as in other members of the subgenus ;
hairs of back about 8 mm. in length. General color above dull dark
buffy (" Dresden brown ") , rather clearer on sides. Under surface
broadly washed with dull buffy ("tawny-olive") ; the bases of the
hairs dark slaty for three-fourths their length. Face rather grayer
than back. Ears longer than in the other allied species, blackish,
contrasting with the general color of the head. Rump generally of
the color of the back, but occasionally more strongly fulvous. Hands
and feet shining grayish, with more or less prominent dark meta-
podial patches. Tail long, finely haired, not penciled, brown, rather
paler proximally below.

no. 2333. MAMMALIA COLLECTED IN PERU BY HELLER— THOMAS. 229
'Skull (pi. 14, fig. 2) about as in 0. dry as, rather more robust than
in 0. minutus.
Dimensions of the type : Head and body, 83 ; tail, 134 ; hind foot,
22.5 ; ear, 15.5. Skull, greatest length, 23.5 ; condylo-incisive length,
21; zygomatic breadth, 13; nasals, 8.2; interorbital breadth, 3.2;
breadth of brain case, 11 ; zygomatic plate, 1.8 ; palatilar length, 9.7 ;
palatal foramina, 4.2 ; upper molar, series, 3.
Type. — Adult female from Torontoy, U.S.N.M. No. 194795.
Orig. No. 255. Collected May 15, 1915. "At timber line."
Sixteen specimens, as follows :
Torontoy, 9,500-14,000 feet, 8 (Nos. 194788, 194795, 194866, 194868-
71, 195103).
Machu Picchu, 6,000-12,000 feet, 3 (Nos. 194872-3, 195104).
Ocobamba Valley, 9,100 feet, 5 (Nos. 194874-5, 194877-9).
After reading Mr. Osgood's remarks 1 about O. dryas and reexam
ining our material I came to the conclusion that this group of
Oryzomys may very well have a special subgeneric name, and would
suggest Microryzomys, with genotype O. minutus. The non-produc
tion forward to the zygomatic plate and the proportionally small
molars would form' the chief diagnostic characters, while, as Mr.
Osgood says, the general appearance of the species shows something
quite special and different from the other members of the large genus
Oryzomys.
Within the group this Peruvian form differs from O. dryas by its
duller color, more like that of the Pichincha O. minutus, and from
both of those species by its longer ears.
I may record that an examination of the young type of O. minutus
received with the Tomes collection in 1907 (B. M. 7.1.1.112) quite
confirms the reference to that species of the Pichincha specimens sent
us by Mr. Soderstrom in 1898. Young as it is, it shows the charac
ters of Microryzomys in all respects.
32. NEACOMYS SPINOSUS Thomas.
Three specimens from San Miguel, 4,500 feet (Nos. 194838-9,
195116). Osgood has drawn attention 2 to the variation from white to buffy
in the belly coloration of this species, a variation repeated in a series
from the Perene collection of Simons. The present specimens have
white bellies, but the hairs in one are white throughout, while in the
other they have slaty bases.
i Field Mus. Nat. Hist Publ., Zool., vol. 10, p. 158, 1914.
2 Idem. p. 160, 1914.

230 PROCEEDINGS OF THE NATIONAL MUSEUM. v01" 58>

33. PHYLLOTIS DARWINI POSTICALIS Thomas.
Twenty -five specimens, as follows :
Huaracondo, 11,000 feet, 9 (Nos. 194566-70, 194713-4, 194716,
194777). Chospyoc, 10,000 feet, 7 (Nos. 194571^, 194718, 194720, 195099).
Machu Picchu, 12,000 feet, 4 (Nos. 194575-6, 194721, 195091).
Ocobamba Valley, 9,100 feet, 2 (Nos. 194578-9).
_ Ollantaytambo, 13,000 feet, 2 (Nos. 194577-194722).
Puquiura, 1 (No. 195110).
As usual in this group the present series shows a good deal of
variation both in size and color, and some of the specimens, notably
those from Chospyoc, tend to resemble the paler subspecies limatus,
which ranges from near Lima eastward to Arequipa, whence a con
siderable number were sent by Simons. The type locality of posti-
calis is Galera, on the heights of the Andes west of Oroya, depart
ment of Junin.
Owing to the manner in which the collector has pulled out the base
of the tail, a tendency to buffy coloration on the hinder rump appears
more prominent in these specimens than in Mr..Simons's skins, but.
although not mentioned in the descriptions, it is present in a variable
degree in most examples of the group.
34. HESPEROMYS FRIDA Thomas.
1917. Hesperomys frida Thomas, Smiths. Misc. Coll., vol. 68, No. 4, p. 1.
April 10, 1917.
A large, comparatively long-tailed species, with the supraorbital
ridges little divergent. Size about as in the largest species of the
restricted genus Hesperomys. Fur close and fine ; hairs of back about
9 nim. in length. General color of specimens in unbleached pelage
grayish drab, becoming more like "wood-brown" posteriorly; in
bleached pelage the posterior back may be nearly cinnamon; sides
lighter and more buffy, the edge of the belly color with a more or less
marked buffy line. Under surface gray, the bases of the hairs slaty,
their tips grayish white. Ears rather large for this genus, colored
like head. Hands and feet pure white. Tail nearly equaling the
head and body in length, inconspicuously grayish brown above, white
on sides and below. Mammae 2-2=8.
Skull (pi. 14, fig. 3) shaped like that of a Phyllotis or of the
smaller species of Ilesperomys, the interorbital region flat, square
edged, but without the broadly divergent ridges found in the other
Hesperomys of this size. Zygomatic plate projected forward, its
front edge vertical or very faintly concave; never distinctly under
cut. Mesopterygoid fossa narrow.
Molars absolutely brachyodont, and thus different from the semi-
hypsodont teeth of Phyllotis.

no. 2333. MAMMALIA COLLECTED IN PERU BY HELLER— THOMAS. 231
Dimensions of the type : Head and body, 102 mm. ; tail, 91 ; hind
foot, 19 ; ear, 18. Skull, greatest length 26.7 ; condylo-incisive length,
24.3; zygomatic breadth, 14; nasals, 10.7; interorbital breadth, 3,8;
breadth' of braincase, 11.6; zygomatic plate, 3; palatilar length, 11.2;
palatal foramina, 5.7 ; upper molar series, 3.9.
Type.— Adult female from Chospyoc, U.S.N.M. No. 194779.
Original No. 96. Collected April 14, 1915.
Nineteen specimens, as follows :
Huaracondo, 11,000 feet, 6 (Nos. 194715, 194770, 194772, 194775-6).
Chospyoc, 10,000 feet, 8 (Nos. 194719, 194726, 194773, 194779-82).
Torontoy, 8,000 feet 1 (No. 194690).
Querafrata, 11,400 feet, 3 (Nos. 194710-11, 194723).
[Anta, Cuzco, 1, B. M. No. 3.2.9.10, O. Garlepp.]
This species differs strikingly from the other equal-sized species
of restricted Hesperomys by the Phyttotis-Yfke build of its interor
bital region, the edges of which are symmetrically concave, and with
out the broadly divergent ridges found in H. venustus and its allies,
and also in Graomys. From Phyllotis it is distinguished by its
absolutely brachyodont molars, these being semihypsodont in that
genus. When writing recently on this subject I erroneously spoke
of the teeth of Phyllotis as brachyodont — a mistake induced by their
less hypsodontism as compared with those of Euneomys. But they
are very markedly more hypsodont than in Hesperomys, this being
the real essential difference. between the two genera.
35. HESPEROMYS CARILLUS MARCARUM Thomas.
1917. Hesperomys carillus marcarum Thomas, Smiths. Misc. Coll., vol. 68,
No. 4, p. 1. April 10, 1917.
Very similar to H. carillus of the Yungas region of Bolivia, but
distinguished (1) by the general color being duller and grayer, with
less buffy infusion; (2) by the upper side of the tail being, like the
sides and below, quite white instead of more grayish buffy; and (3)
by the palms and soles being considerably more hairy. In true
carillus the soles, along their middle line at least, are naked almost
to the heels, while in all the five available specimens of marcarum,
taken at different seasons, the soles are hidden by the hairs to the
level of the fifth or sixth sole pad.
Dimensions of the type, measured on skin: Head and body
(stretched), 82; tail, 46; hindfoot, 17.7. Skull — nasals, 9; interor
bital breadth, 3.9; palatilar length, 9.2; palatal foramina, 5; upper
molar series, 3.7.
Type: Adult skin from Lauramarca, B. M. No. 3.2.9.8. Original
No. 464. Collected June 25, 1899 by O. Garlepp. Presented by
Oldfield Thomas.

232 PROCEEDINGS OF THE NATIONAL MUSEUM. V0L- 5S-
Five specimens, as follows :
La Eaya Pass, 14,000 feet, 2 (Nos. 194691-2).
[Lauramarca, Cuzco, 2 (Nos. 3.2.9. 8-9, B. M.), O. Garlepp.]
[Sucre, Cuzco, 1 (No. 3.2.9.11, B. M.>, O. Garlepp.]
The specimens in the Heller collection, like most of those from
La Raya Pass, are without skulls, but are clearly the same as the
Cuzco examples collected by Garlepp, which I have long thought
might be distinguishable from Hesperomys carillus. Undoubtedly
the two forms are very similar, but the uniformly greater hairiness
of the soles of the Cuzco series would seem to justify subspecific
distinction. 36. EUNEOMYS (AULISCOMYS) PICTUS Thomas.
Forty-two specimens, as follows:
Huaracondo, 11,000 feet, 7 (Nos. 194515-6, 194518, 194520, 194526,
194717, 194777).
Ollantaytambo, Ocobamba Pass, 13,000 feet, 18 (Nos. 194527-9,
194538, 194706-9, 194774, 194977-9, 194980-6).
La Raya Pass, 14,000 feet, 16 (Nos. 194533-1, 194539, 194543,
194546, 194966-76 .
This is a common and widely spread species in the highlands of
Peru. In size and in the development of the ochraceous or tawny
tints of the posterior body there is a very great difference between
young adults and old adults ; and on this account I confess to being
somewhat doubtful of the difference from E. pictus of Osgood's
" Phyllotis {Auliscomys) decoloratus " 1 from Puno, which is said to
be distinguished by its smaller size and less strongly colored rump.
The British Museum contains examples from two of the three locali
ties mentioned by Osgood for decoloratus, and these are quite similar
to normal E. pictus in every respect.
37. RHIPIDOMYS LEUCODACTYLUS Tschudi.-
Ten specimens, as follows :
Machu Picchu, 6,000 feet, 1 (No. 194493).
Rio San Miguel, 4,500 feet, 4 (Nos. 194498-500, 195097).
Santa Ana, 3,000 feet, 1 (No. 194501).
[Ocobamba, Cuzco, 2, Nos. 98.11.6.19-20, B. M., O. Garlepp.]
[Marcapata, Cuzco, 2, Nos. 3.2.9.6-7, B. M., O. Garlepp.]
Quite agreeing with Garlepp's specimens from Ocobamba and
Marcapata, Cuzco, which after seeing the type in Neuchatel, I have
taken for R. leucodactylus, and equally distinct from the larger R
lucullus of Vitoc.

1 Field Mus. Nat. Hist. Publ., vol. 10, p. 191, 1915.

no. 2333. MAMMALIA COLLECTED IN PERU BY HELLER— THOMAS. 233
38. THOMASOMYS AUREUS Tomes.
Five specimens, as follows :
Torontoy, 9,000-10,000 feet, 4 (Nos. 194817-20).
Ocobamba Valley, 9,100 feet, 1 (No. 194826).
The identity of these specimens with average examples of the
somewhat variable T. aureus of Ecuador is remarkable. Compared
with a number of specimens from the neighborhood of Pichincha
they at first seem different by their more buffy belly ; but not only
do two examples among the Pichincha series have the same buffy
belly, while two others are intermediate, but it is also of the same
deep buffy in the type, which came from Gualaquiza.
The hind feet are more prominently particolored in the Torontoy
set, less so in the specimen from Ocobamba, which closely matches
some of the Pichincha series.
The majority of our Pichincha set are from about 7,000 feet, but
one is from 12,000 feet, consequently a topotype of Allen's T. a.
altorum, as to the validity of whose distinction from T. aureus I am'
most doubtful. 39. THOMASOMYS NOTATUS Thomas.
1917. Thomasomys notatus Thomas, Smiths. Misc. Coll., vol. 68, No. ¦ 4,
p. 2, April 10, 1917.
A medium-sized species with a dark dorsal stripe, broad feet, and
well-marked metatarsal patches.
Size far smaller than in T. aureus, almost as in cinereus. Fur
close, thick, rather woolly ; hairs of back 6-7 mm. in length. General
color above, in adults, ochraceous tawny, darker than the color so
named in Ridgway ; grayer on head, more tawny posteriorly ; an ill-
defined blackish streak down the middle of the back, from withers to
rump, varying much in distinctness, but always perceptible. Under-
surface soiled whitish, the hairs slaty basally, dull whitish termi
nally ; lips and throat completely white, the hairs white to their bases.
Hands above silvery whitish without darker markings on metacar
pals ; feet, on the other hand, only white along the edges and on the
digits ; the tarsus and metatarsus broadly and prominently brown.
The feet themselves unusually broad for a Thamasomys, more as in
Rhipidomys. Tail hairy, slightly penciled, uniformly dark brown
above and below.
Skull (pi. 14, fig. 4) in general build like that of a miniature
T. aureus, except that the zygomata are not so convergent for
wards. Nasals narrow, their borders curiously sinuate, converging at
their middle and then again diverging (or at least remaining strictly
parallel) in their posterior third. Interorbital region narrow, its
edges slightly raised to form low supraorbital ridges, similar to,
though smaller than, those of T. aureus; the ridges scarcely extend-

234 PROCEEDINGS OF THE NATIONAL MUSEUM. V0L- 58-
ing on to the braincase — very different from the broadly divergent
ridges of typical Rhipidomys. Zygomatic plate narrow, with ver
tical front edge, little projected forwards. Palatal foramina ending
level with the front of m1. Molars rather small in proportion to the
size of the skull, conspicuously smaller than in the species of the
T. aureus group.
Dimensions of the type: Head and body, 128; tail, 155; hindfoot,
27; ear, 18.5. Skull — greatest length, 33; condylo-incisive length,
30; zygomatic breadth, 17.4; nasals, 12; interorbital breadth, 4.2;
breadth of braincase, 14; palatilar length, 13; palatal foramina, 7.1;
post-f oraminal palate, 4.6 ; upper molar series, 4.6.
Type. — Adule male from Torontoy, U.S.N.M. No. 194548 ; original
number 173. Collected May 15, 1915.
Seven specimens, as follows :
Torontoy, 9,500 feet, 6 (Nos. 194547-8, 184894-7).
Machu Picchu, 8,000 feet, 1 (No. 194898).
From the point of view of systematic arrangement this well-
marked species presents a problem of considerable difficulty ; for with
the general skull shape of the less typical species of the genus
Thomasomys, it has comparatively broad feet; showing that it is a
climbing animal ; and it is just the broad feet which are supposed to
characterize the members of Rhipidomys, while those of Thomas
omys, more or less ground living, have long narrow feet. Moreover,
the doubt as to its proper generic position is complicated by the fact
that, while the more strongly marked species of Rhipidomys have
broadly divergent supraorbital ridges, this can not be said of all
of those which have been included in the genus.
40. THOMASOMYS GRACILIS Thomas.
1917. Thomasomys gracilis Thomas, Smiths. Misc. Coll., vol. 68, No. 4. p. 2.
April i0, 1917.
A very small species allied to T. boeops.
Size about the smallest of the genus. General appearance very
much as in T. boeops or a miniature T. notatus. Color above dark
grayish buffy or clay color (approximately "Dresden brown" of
Ridgway), the posterior median area usually darker, the darkening
not defined enough to be called a stripe. In some specimens the
color varies toward cinnamon, but it is not clear whether this varia
tion is seasonal or individual. Undersurface soiled grayish buffy,
not sharply contrasted; the hairs slaty basally, dull pinkish buff
terminally. Ears fairly large, blackish, contrasting with the gen
eral color of the head; a small patch behind their lower bases pale
buffy. Hands and feet with brown metapodials and light digits.
Tail long, well haired, blackish brown, -scarcely lighter below ; the
extreme tip sometimes white.

no. 2333. MAMMALIA COLLECTED IN PERU BY HELLER— THOMAS. 235
Skull (pi. 14, fig. 5) quite of the general make of that of T. boeops,
but conspicuously smaller. Interorbital region narrow, its edges just
squared, but not rigged. Brain case smooth, rounded, little ridged.
Palatal foramina well open, reaching back just past the anterior
end of m1. Bullae of normal size, much smaller than in T.
taczanowshii. Dimensions of the type : Head and body, 82 ; tail, 120 ; hind foot,
21.5; ear, 16. Skull — greatest length, 26.1; condylo-incisive length,
22.6; zygomatic breadth, 13.6; nasals, 9; interorbital breadth, 3.7;
breadth of brain case, 12 ; palatilar length, 10.2 ; palatal foramina, 5.5 ;
upper molar series, 3.6.
Type.— Adult male from. Machu Picchu. U.S.N.M. No. 194816.
Original number 321. Collected June 8, 1915.
Twenty-one specimens, as follows:
Torontoy, 10,700-14,000 feet, 7 (Nos. 194783-5, 194789-90, 194792,
194797). Machu Picchu, 12,000-14,000 feet, 5 (Nos. 194798, 194800, 194802-3,
194816). Ocobamba Valley, 9,100 feet, 2 (Nos. 194807-8).
Lucma, 10,000-11,400 feet, 7 (Nos. 194791, 194810-5).
This pretty little species is readily distinguished by its small size,
buffy washed belly, and the strictly normal characters of its skull ; the
incisors not thrown forward as in T. daphne, nor the bullae enlarged
as in T. taczanowsMi. 41. THOMASOMYS DAPHNE Thomas.
1917. Thomasomys daphne Thomas, Smiths. Misc. Coll., vol. 68, No. 4,
p. 2. April 10, 1917.
A small, short-eared species, with its incisors thrown forward.
Size rather greater than in T. gracilis. General external appear
ance very much as in that animal, except that the color is duller and
more drabby, and no dorsal darkening is perceptible. Color of
back rather more buffy than " Saccardo's umber " ; of undersurf ace
slaty gray broadly washed with buffy, the line of demarcation not
defined. Head grayer than back. Ears smaller than in T. gracilis/
their color brown, not contrasting strongly with the head; buffy
patch below outer base of ear present but not conspicuous. Hands
and feet pale brown, with lighter digits; metapodial markings not
strongly contrasted. Tail not heavily haired, brown above and be
low. One specimen with a white tip, the other not.
Skull (pi. 15, fig. 1) decidedly larger than that of T. gracilis,
about equaling that of boeops. Interorbital region comparatively
broad, its edges not ridged. Palatal foramina short, ending some
way in front of m1 and narrow, not widely open ; their median sep
tum broadened and flattened posteriorly. Bullae small.

236 PROCEEDINGS OF THE NATIONAL MUSEUM. vol^uS.

Incisors differing from those of every other member of the genus
by being distinctly thrown forward, their angle with the upper tooth
row, measured as recently described,1 84° and 85° in the two speci
mens, while this angle comes out at about 70°-76° in T. gracilis and
the other members of the genus examined. Molars as usual.
Dimensions of type.— Head and body, 92 ; tail, 133 ; hindfoot, 23.5 ;
ear, 16. Skull— greatest length, 27.7; condylo-incisive length, 26.2;
zygomatic breadth, 14.2; nasals, 8.5; interorbital breadth, 4.7;
breadth of braincase, 13; palatilar length, 12.1; palatal foramma,
5.3 ; post f oraminal palate, 5 ; upper molar series (worn) , 4.2.
Type.— Old female from Ocobamba Valley, U.S.N.M. No. 194902.
Original number 521. Collected July 29, 1915.
Two specimens from Ocobamba Valley, 9,100 feet (Nos. 194809 and
194902). As already noticed, this species is remarkable for the unusually-
forward set , of its incisors, which distinguishes it from every other
member of the genus, and probably indicates some difference in its
habits, which are perhaps of a more fossorial or at least more defi
nitely terrestrial nature.
42. THOMASOMYS TACZANOWSKII Thomas.
One specimen, (No. 194876) from Ocobamba Valley.
This determination is pf necessity somewhat provisional, and can
only be settled when modern topotypes are available. The type has
been skinned out of spirit, and is much discolored, while its ears are
shrunk, as is always the case with specimens so treated. The skulls
agree fairly closely, the size being about the same, the nasals simi
larly sinuate along their sides, as in T. notatus, and the bullae
similarly larger than in the T. gracilis and the other small species to
which this mouse has so strong a general resemblance.
43. AKODON SURDUS Thomas.
1917. Akodon surdus Thomas, Smiths. Misc. Coll., vol. 68, No. 4, p. 2. April
10, 1917.
A large, dark-colored species allied to A. mollis.
Size comparatively large. Build stout and heavy. Fur rather
coarse. General color above dark olivaceous gray (near "sepia11
Ridgway) ; under surface, soiled grayish, and hairs slaty basally,
dull buffy or drab terminally ; line of demarcation vague.
Ears of medium size, colored like head. Hands and feet grayish
brown above, the flesh of the soles blackish. Tail fairly long, finely
haired, dark brown, scarcely lighter below.
Skull (pi. 15, fig. 2) solidly built, its profile evenly convex above.
Muzzle thick and heavy. Interorbital region broad, its edges squared.
• Ann. and Mag. Nat. Hist., ser. 8, vol. 18, p. 302, footnote. 1916.

so. 2338. MAMMALIA COLLECTED IN PERU BY HELLER— THOMAS. 237
Zygomatic plate broad, projected forward, its front edge vertical.
Palatal foramina widely open. Bullae of medium size.
Dimensions of the type. — Head and body, 110 mm. ; tail, 80 ; hind
foot, 22.5; ear, 16, Skull — greatest length, 28; condylo-incisive
length, 26.2 ; zygomatic breadth, 14.3 ; nasals, 10.4 by 3.8 ; interorbital
breadth, 5 ; palatilar length, 12.2 ; palatal foramina, 6.6 ; upper molar
series, 4.9.
Type.— Old male from Huadquina, U.S.N.M. No. 194663. Origi
nal No. 835. Collected October 28, 1915.
Eighteen specimens, as follows:
Idma, 6,000 feet, 6 (Nos. 194656-8, 195077, 195079-80).
Huadquina, 5,000 feet, 7 (Nos. 194661-3, 194694, 195087-9).
Paltaybamba, 5,000 feet, 1 (No. 195068).
Santa Ana, 4 (Nos. 195081-4).
This Akodon differs from its nearest ally, A. mollis, by its stouter
build and smokier color, without tinge of buffy. The animal is of
interest in connection with its strong external resemblance to the
species here called Microxus torques. The two are found, respec
tively, at low (5,000-6,000 feet) and high (8,000-14,000 feet) alti
tudes and apparently represent the lowland and highland forms of
northern Peru, distinguished by Osgood merely as subspecies of
A. mollis — a closeness of relationship which, as explained below,
under Microxus torques, I am not prepared to accept.
44. AKODON BOLIVIENSIS (Meyen).
Eighty-six specimens, as follows:
Huaracondo, 40 (Nos. 194664-5, 194669, 194671-2, 194731-2,
194734-5, 194739-40, 194998-195024, 195101-2).
Chospyoc, 10,000 feet, 3 (Nos. 194673, 194742-3).
Machu Picchu, 14,000 feet, 1 (No. 194744).
Ollantaytambo, 13,000 feet, 22 (Nos. 194674-5, 194746-59, 194951-3,
194959-61). Ocobamba Valley, 9,100 feet, 9 (Nos. 194760-4, 194962-5).
Paltabam'ba, 5,000 -feet, 3 (Nos. 194642, 194644-5).
Lucma, 9,000 feet, 1 (No. 194646).
Chiarapata, 11,200 feet, 2 (Nos. 194697-8).
Santa Ana, 3,500 feet, 2 (Nos. 194659-60).
La Raya Pass, 14,000 feet, 3 (Nos. 194695-6, no skulls, identification
not positive, 195090 in alcohol).
The common small grass mouse of eastern Peru and Bolivia.
[AKODON (CHALCOMYS) AEROSUS BALIOLUS Osgood].
[One specimen in the British Museum from Callanga, Cuzco. O.
Garlepp. No. 98.11.6.2.]
I record this under the name given by Mr. Osgood to the Inambari
form of A. aerosus, but do not express any opinion as to its degree of
-difference from true aerosus,

238 PROCEEDINGS OF THE NATIONAL MUSEUM. V0L- 58-

Mr. Heller did not capture any representative of the subgenus
Ohalcomys. 45. BOLOMYS AMOENUS Thomas.
Two specimens from Huarocondo, 11,000 feet (Nos. 194724-5).
Type locality, Rio Colca; other specimens in the British Museum
from Sangero, Department Puno, and San Anton, Titicaca.
46. CHROEOMYS INORNATUS Thomas.
1917. Chroeomys inornatus Thomas, Smiths. Misc. Coll., vol. 68, No. 4,
p. 2. April 10, 1917.
Near C. pulcherrimus, but ears smaller and special markings re
duced. Size and general characters about as in G. pulcherrimus. Color
most nearly as in G. p. crwceri,1 to which there is a strong resem
blance throughout. Body a duller olivaceous gray; crown and
median dorsal area suffused with dark cinnamon buff, shoulders and
sides more grayish, a coloration which gives a deceptive resemblance
to the members of the genus Abrothrix. Underside gray, the bases
of the. hairs broadly slaty, their tips dull whitish gray; the result
ing color conspicuously less whitish and less contrasted with the gen
eral tone of the back and sides. Nose spot rich ochraceous, and
this color extends on the face up to the forehead and surrounds the
eyes. Ears apparently shorter than in C. pulcherrimus; the color of
the visible parts warm brown, not contrasted with the general color
of the head. Post- auricular patches comparatively very inconspicu
ous; the tips only of the hairs on this part grayish white, and the
extent of the patches reduced, surpassed behind by the ears them
selves, and widely separated from the gray on the sides of the neck.
Hands white; feet with the metatarsals pale cinnamon, the digits
whitish. Claws apparently less elongated than in the allied species.
Tail well haired, blackish along the middle line above, pale cinna
mon on sides, whitish below.
Skull (pi. 15, fig. 3) essentially similar to that of C. pulcherrimus,
but the bullae rather smaller. The type has its incisors as strongly
colored as in Ahodon, which is not usual in Chroeomys, but the sec
ond specimen is intermediate in this respect.
Dimensions of the type. — Head and body, 122 ; tail, 80 ; hindfoot,
24.5; ear, 16.2 Skull — greatest length, 30; condylo-incisive length,
27.6; zygomatic breadth, 15.6; nasals, 12.4; interorbital breadth, 5;
palatilar length, 12.5 ; palatal foranina, 6.9 ; upper molar series, 4.3.
Type. — Adult female from Ollantaytambo. U.S.N.M. No. 194685.
Original No. 457. Collected July 20, 1915.
1 See Ann. and Mag. Nat. Hist., ser. 7, vol. 7, p. 186, 1901.
2 Ear of other specimen measured as 18 mm.

no. 2333. MAMMALIA COLLECTED IN PERO BY HELLER— THOMAS. 239
- — ,
Three specimens, all from Ollantaytambo (Nos. 194685-6,195092).
This species is less typically Chroeomys-lfke in all the characters
used to distinguish that genus from other members of the Akodon
group; for the coloration is less abnormal, the claws are less elon
gated, the incisors are darker colored, and the bullae are smaller
than in the hitherto known species of the genus. There is, however,
no question that it is a Chroeomys, and that its nearest alliance is
with G. pulcherrimus cruceri, with which it most nearly agrees in
general color. 47. OXYMYCTERUS PARAMENSIS Thomas.
Three specimens, as follows:
Chospyoc, 10,000 feet, 1 (No. 194699).
Ollantaytambo, 13,000 feet, 2 (Nos. 194700, 194703).
Quite indistinguishable from the typical specimens of this species
which came from Choquecamate, northwest Bolivia.
48. MICROXUS TORQUES Thomas.
1917. Microxus torques Thomas, Smiths. Misc. Coll., vol. 68, No. 4, p. 3.
April 10, 1917.
Like M. mimus, but the zygomatic plate not so strongly narrowed
and slanting. Also superficially like Akodon surdus.
Size averaging slightly greater than in M. mimus. Fur close, soft,
and woolly ; hairs of back about 10 mm. in length. General color
smoky or olivaceous gray, quite as in M . mimus, and also very similar
to the color of Akodon surdus, although, owing to the softer texture
of the hair, there is a difference in appearance. Under surface little
lighter than upper, a vague darker streak often present in the sternal
region. Ears rather short, colored like head. Hands and feet gray
ish brown above; soles flesh-colored, not blackish, as in Akodon
surdus. Tail long, finely haired ; brown above, scarcely lighter below.
Skull (pi- 15, fig. 4) , as compared with that of M. mimus, very
similar in most respects. Upper profile not perhaps quite so flattened
in the frontal region, and therefore more approaching the even con
vexity found in Akodon surdus. Interorbital space broad, smooth,
its edges scarcely squared. Zygomatic plate decidedly broader than
in M. mimus; its front edge, although distinctly slanting, yet not so
slanting as in mimus, and with a certain slight convexity* in its upper
third; this part therefore tending toward the condition found in
Akodon. Palatal foramina well open, ending opposite the anterior
third of first molar.
Dimensions of type.— Head and body, 102 mm.; tail, 94; hindfoot,
22.3 ; ear, 17. Skull— greatest length, 28 ; condylo-incisive length, 25 ;
zygomatic breadth, 14.3; nasals, 10.2 by 3; interorbital breadth, 5;
breadth of brain case, 12.5 ; zygomatic plate, 2 (1.5 in the type of

240 PROCEEDINGS OF THE NATIONAL MUSEUM. V0L- 5S-
M. mimus) ; palatilar length, 11.8 ; palatal foramina, 6.5 ; upper mo
lar series, 4.5.
Type.— Old male from Machu Picchu, U.S.N.M. No. 194607.
Original No. 276. Collected May 28, 1915.
Fifty -eight specimens, as follows :
Torontoy, 9,500-14,000 feet, 39 (Nos. 194581-2, 194595, 194602-4,
195025-57). Machu Picchu, 8,000-13,000 feet, 11 (Nos. 194605-8, 194610-11,
194619,194676-7,194693,194745). Ocobamba Valley, 9,100 feet, 3 (Nos. 194632-3, 194635).
Quirapata, 11,400 feet, 5 (Nos. 194647-9, 194680-1).
This species is distinguishable from M. mimus by its broader and
less characteristically Microxine zygomatic plate, but is otherwise
very similar to that animal. Osgood's Akodon mollis orophilus is
said to be " more fulvous than A. m. altorum" which is anything but
the case with the present animal ; and his A. m. orientalis is a low-
land form and much darker in color.
The proper treatment of this animal is a most difficult problem
on account of its annectant characters. Originally two groups were
known, Akodon with normal claws and vertical zygomatic plate, and
Oxymycterus with elongated claws and slanting plate. Then cer
tain species were discovered which had normal claws and slanting
plate, and for these, after they had been referred either to Akodon
or Oxymycterus, I formed the genus Microxus, with M. mimus as
genotype. Next Mr. Osgood, getting a pair of forms, respectively
lowland and highland, corresponding to the Akodon surdus and Mi
croxus torques of the present paper, treated them merely as sub
species of a common form, Akodon mollis, a treatment which appears
to me to give far too little value to the characters of the zygomatic
plate. But, on the other hand, I quite admit that while the zygomatic
plate of the earlier described species was strongly and characteristi
cally different from that of Akodon, that of M. torques (and I pre
sume of Akodon mollis orophilus and orientalis) is more or less inter
mediate between the two. We have therefore to decide whether
Microxus shall be amalgamated with Akodon, ignoring its peculiar
zygomatic plate, or whether we shall recognize Microxus and put
torques, orophilus, and orientalis into it, where they would form a
group of species annectant with Akodon. Although I am by no
means completely satisfied this latter course seems on the whole the
most advisable for the present, and I have therefore treated Mr.
Heller's animal as a member of the genus Microxus.
The above was written before the spirit specimens came into my
hands. A study of these shows very strongly the essential difference

no. 2333. MAMMALIA COLLECTED IN PERU BY HELLER— THOMAS. 241
between the two animals under discussion. The long head, especially
the long muzzle, and the small eyes, give the Microxus quite a dif
ferent aspect to that of the Akodon with its blunt snout and normal
eyes, and I now feel no hesitation in considering them as belonging
to different genera. 49. DASYPROCTA KALINOWSKII Thomas.
Adult female, No. 194485, Pumachaca,' Urubamba Valley, 5,000
feet. Taken by E. C. Erdis.
The second known example of this striking species. The specimen
is in more faded pelage than the type, but agrees with it in all essen
tial respects, though the yellow of the belly is rather less strongly
marked. [DASYPROCTA VARIEGATA (Tschudi).]
[Three specimens in the British Museum from Callanga, Cuzco.
Nos. 98.11.6.10-12. O. Garlepp.]
[LAGOSTOMUS CRASSUS Thomas.]
[A skull, the type, in the British Museum from Santa Ana, Cuzco.
No. 97.10.3.16. J. Kalinowski.]
Like the Abrocoma described by Mr. Eaton, this Peruvian Viz-
cacha is no doubt now extinct. The skull was found buried in the
sand. 50. VISCACCIA SATURATA Thomas.
Seven specimens as follows :
Ollantaytambo, 13,500-14,000 feet, 4 (Nos. 194466-9).
Between Puquiura and Huadquina, 14,000 feet, 3 (Nos. 194479,
194481,194483). The Puquiura Pass specimens agree absolutely with the typical
series of V. saturata, while those from Ollantaytambo are a little
lighter, and tend to approach the palid form V. arequipae.
51. VISCACCIA AREQUIPAE Thomas.
One specimen, female, from La Raya Pass, 14,000 feet (No.
194478). 52. CAVIA TSCHUDII TSCHUDII Fitzinger.
Three immature females from La Raya Pass, 14,000 feet (Nos.
194490-2). [Four specimens in the British Museum from Urubamba, Cuzco,
9,000 feet, Nos. 3.2.9.13-16. O. Garlepp.]
The La Raya Pass specimens have grayish bellies, while those from
Urubamba are buffy below, but the former are all immature.
181404 — 20— Proc.N.M. vol.58  16

242 PROCEEDINGS OF THE NATIONAL MUSEUM. TOI" 5S-
53. ODOCOILEUS PERUVIANUS Gray.
Six specimens as follows :
Ollantaytambo, 3 males and 1 female (Nos. 194300, 104304-5,
194299). Chospyoc, Huaracondo, 1 male (No. 194301).
Paso Panticalla, 1 female (No. 194306).'
54. MAZAMA AMERICANA WHITELYI Gray.
Female, Uvini, Rio Cosireni (No. 194308).
This is clearly Tschudi's Cervus rufus, but on geographical
grounds it may be provisionally considered as suhspecifically distinct
from the Guianan and Brazilian form, to which that name, synony
mous with americanus, properly belongs.
The type skull of Gray's Coassus whitelyi, however (B. M. No. 73.
6. 27. 2), coming quite from this region, appears to me to be referable
to this larger Brocket, and not, as Lydekker has placed it, to the
smaller Mazama tschudii, the Cervus nemorwagus of Tschudi.
Unfortunately that type skull is without skin and quite young,
while Mr. Heller's example is old, and we have no Peruvian speci
mens connecting the two. An absolute identification must therefore
await further material.
The hairs on the nape of this specimen are not reversed, and the
skull measures 204 mm. in condylobasal length ; tooth-series (worn)
63 mm. The anterior palatine foramina are no less than 37 mm. in
length. 55. MAZAMA, species.
Imperfect skull of a male from Santa Ana, 3,480 feet (No. 194307) .
Collected by E. C. Erdis.
This skull (found on ranch of, and presented by, Alberto Duque)
consists only of the frontals and brain case, without teeth, and is not
certainly determinable. It seems, however, to indicate the presence
in this region of a small Mazama of the rufina-bricenii group, as it
appears too small to belong to M . tschudii, at least if that species is
really as large as M. simplicicornis, of which it is said to 4be the
Peruvian representative. 56. HIPPOCAMELUS ANTISIBNSIS D'Orbigny.
Male and female from Ollantaytambo, 14,000 feet (Nos. 194298,
194303). 57. LAMA HUANACHUS CACSILENSIS Lonnberg.
Two males, from La Raya Pass, 16,000-17,000 feet (Nos. 194292,
194294). All the guanacos of the highlands of Peru and Bolivia may ap
parently be distinguished from those of Chile and Patagonia by

no. 2333. MAMMALIA COLLECTED IN PERU BY HELLER— THOMAS. 243
their smaller size, as gauged by the skull length. Professor Lonn
berg's name cacsilensis, from the plateau of Cacsile, Nunoa, quite
near La Raya Pass, is available for them.
The broadly rounded choanal opening of the palate, so striking in
Lonnberg's figure of the type of cacsilensis, proves to be a character
quite untrustworthy. For while the guanaco usually has a narrow
V-shaped opening, and the vicugna a broad rounded one, the British
Museuhi contains specimens forming exceptions to the rule in both
the species, and I therefore consider the type of cacsilensis to be
another such exception.
In color there is less difference between cacsilensis and true huana-
chus than appears to be the case in the corresponding races of the
vicugna. The type locality of huanachus may be taken as Quillota, Chile, the
only exact locality mentioned by Molina. In this region that author
states that during the winter the guanacos come down from the
mountains into the plains.
Sexual difference in these animals is well marked in the sizes of
the incisors and canine teeth, so that skulls can be sexed at a glance.
58. LAMA VICUGNA MENSALIS Thomas.
1917. Lama vicugna mensalis Thomas, Smiths. Misc. Coll., vol. 68, No. 4,
p. 3. April 10, 1917.
Size slightly less than in true vicugna and teeth much smaller.
Color more strongly fulvous.
The type locality of 'Molina's Gamelus vicugna should apparently
be taken as " the part of the Chilean Cordillera facing the Prov
inces of Ooquimbo and Copiapo," and an example in the British
Museum from Catamarca may provisionally be said to represent that
animal ; for the chain of the Andes could be no barrier to a vicugna,
so that the forms of the eastern and western slopes would no doubt
be the same.
From Peru and Bolivia quite a number of specimens are available,
and as compared with .the Catamarca specimen these all agree in
having a slightly shorter skull, with shorter muzzle and nasal open
ing, and much smaller teeth, the combined length of the upper molars
being usually well under 50 mm. (45 in the type, 44 and 45 in Lonn
berg's two specimens) , while the length in the Catamarca vicugna is
54 mm. The general color of the northern form is a strong cinna
mon-tawny, the light underside white and sharply contrasted, while
in the specimen of true vicugna the color is a colder and more gray
ish brown, somewhat like " avellaneous " of Ridgway. In this respect^
Mr. Heller's specimen is less characteristic than usual, duller and
browner than in any others of the series of mensalis available. No
doubt therefore considerable variation will be found to occur in the

244 PROCEEDINGS OF THE NATIONAL MUSEUM. V0L- 58-
color where series of the forms are collected, and there will be some
intergradation in the dimensions of the skull and teeth.
The northern form may therefore be considered as a subspecies of
the southern and may have the above name applied to it.
The chief skull dimensions of the Catamarca specimen and of the
type of mensalis are, respectively, as follows: Greatest length, 244
and 240; condylobasal length, 225, 224; greatest breadth, 122, 123;
nasal opening, 92, 87; palate length, 116, 111; length of molars,
54,45. Type locality. — Incapirca, Zezioro, Junin, Peru; altitude, 17,700
feet. Other specimens in the British Museum from the Puna region,
Peru (E. P. Ashmore), Cordillera, north of Titicaca, 17,000 feet
(Maj. H. S. Toppin), Choquecamate, Bolivia (P. O. Simons"), and
"Bolivia" (T. Bridges).
Type.— Male adult. British Museum No. 97.10.3.18. Collected
May 30, 1890, by J. Kalinowski.
Male and female from La Raya Pass, 16,000 feet (Nos. 194296-7).
59. OROLESTES INCA Thomas.
1917. Orolestes inca Thomas, Smiths. Misc. Coll., vol. 68, No. 4, p. 3. April
10, 1917.
Generic characters. — Like Goenolestes, but proportions of teeth
different. Externally quite as in Goenolestes.
Skull (pi. 15, fig. 5) very like that of Goenolestes; zygomata
broader and more flattened, especially anteriorly, where the height
is some five or six times greater than the thickness. In Goenolestes
the bar more nearly approaches the cylindrical, its thickness being
from a half to three-quarters the height. Anteorbital vacuities
present, as in C. obscurus. Opening of anteorbifal foramina slightly
further back, over the anterior third or middle of the first molari-
form tooth.1 Palatal foramina and vacuities quite as in Goenolestes.
Lower jaw without special peculiarities, though the two rami are
perhaps less extensively in contact, and are in consequence less firmly
united. Teeth similar in number to those of Coenolestes, the formula, as I
should now read it, being I. f; C. T; P. -f; M, §¦ X 2 = 46.
Upper incisors as in Goenolestes, except that the fourth is nar
rower, more pointed, and in fact more like a premolar than the third,
and stands a little way back from it, while in Goenolestes it is simi
lar to and stands close behind the third.2 Canines short, scarcely or
not longer than incisors, double-rooted, premolariform in shape,
quite unlike the long, single-rooted, normally-shaped canines of
1 M T of the Catalogue of Marsupials and of my original description of Goenolestes, p *
as I now consider it should be reckoned.
2 The figured skull of Coenolestes, as then explained, was abnormal in this respect.

no. 2333. MAMMALIA COLLECTED IN PERU BY HELLER— THOMAS. 245
Goenolestes. First premolar minute, perhaps one fifth to one tenth
the bulk of the second, its tip not or barely as high as the cingular
cusp of the canine; in Goenolestes the first and second premolars are
subequal, sometimes one and sometimes the other slightly the larger.
Ps (the sector or pm* of the catalogue) of about the same size as in
Goenolestes, its thickness transversely subequal anteriorly and poste
riorly, while in Goenolestes it is thicker behind than in front, as is
more usual in marsupials generally. Molariform teeth (p4 and
molars) as in Goenolestes, the minute m3 perhaps averaging even
smaller. Lower teeth more like those of Coenolestes than is the case with
the upper, but there is a corresponding, though slighter, reduction
in the relative size of the posterior incisors, the canine and anterior
premolars. As a genus this animal is most readily distinguishable from
Coenolestes by the shortening and the double-rooted condition of
the upper canines, and the reduction in the relative size of p1.
Specific characters. — Externally hardly distinguishable from
Coenolestes fuliginosus,. being of the same size and proportions, and
of the same dull grayish-brown (near " clove-brown ") color above,
C. obscurus being more strongly brown in tone, though this difference
may possibly be due to the fading of the specimens of the latter.
Undersurf ace paler brown, the ends of the hairs drabby brown ; in
G. fuliginosus the ends of the belly hairs are dull grayish white.
Ears with a narrow rim of whitish or glossy hairs, this whitish rim
not perceptible in the specimens of Goenolestes. Hands and feet
brown on metapodials, lighter on digits. Tail averaging about the
length of the head and body, thinly haired, either uniformly dull
brown or slightly mottled with dull whitish.
Skull and teeth as described above.
Dimensions of four specimens : Male 194401 (type) , bead and body,
120; tail, 108; hindfoot, 22; ear, 15. Male 194381, head and body,
122; tail, 113; hindfoot, 22.5; ear, 15. Female 194397, head and
body, 106; tail, 104; hindfoot, 21.5; ear, 15. Female 194398, head
and- body, 105; tail, 125; hindfoot, 22.5; ear, 15.
Skulls of male and female, the first the type : Greatest length, 33,
31.4; condylobasal length, 32.5, 31; zygomatic breadth, 14.8, 14.8;
nasal length, 17.5, 15.6; intertemporal breadth, 7.8, 7.8; breadth of
brain case, 12.4, 12; palatal length, 19, 18; palatal foramina, 7.3, 7;
upper tooth series, 18.3, 17.5; combined length of three anterior
molariform teeth (p4 to m2), 5.4, 5.3; lower tooth series, 17. 16.6;
length of i„ 5.2, 4.9 ; three anterior lower molariform teeth, 5.8, 5.8.
Type.—A.c\vlt male from Torontoy. U.S.N.M., No. 194401. Origi
nal No. 248. Collected May 14, 1915.
Seventeen specimens as follows :

246 PROCEEDINGS OF THE NATIONAL MUSEUM. vol/58.
Torontoy, 9,500-14,000 feet, 7 (Nos. 194381-2, 194386, 194391,
194397-8, 194401).
Machu Picchu, 12,000-43,000 feet, 6 (Nos. 194415-16, 194418,
194420-1, 194428).
Ocobamba Valley, 9,100 feet, 4 (Nos. 194429, 194431-2, 194434).
This animal is the prize of the collection and really represents a
most interesting discovery. Specimens of the family Coenolestidae
are still exceedingly rare in collections, and even if the present
series had been referable to the original genus Goenolestes, they
would have been of great value. And this is of course still more the
case now that they prove to represent a second genus of this archaic
group. The recent specimens of the Coenolestidae as yet known are as fol
lows: The type of Hyracodon fuliginosus Tomes, Ecuador, B. M. No.
7.1.1.191. A young specimen preserved in spirit. This historic ex
ample, described in 1863, was not accessible when I wrote my paper
on Goenolestes in 1895.
Two skins (one skull only) from Gualea, Ecuador, collected in
1914 and presented by W. Goodfellow, Esq., B. M. Nos. 15.11.25.5-6.
These undoubtedly represent true fuliginosus, and are of particular
value, owing to the type's age and condition rendering it useless
for any close comparison.
Four specimens from La Selva Estate, Bogota. Collected in 1895
by an Indian in the employ of Mr. G. D. Child. B. M. Nos. 96.1.7.1-3,
and American Museum of Natural History No. 10559, the latter
being the basis of Miss Dederer's paper on the genus (1909). The
original series of C. obscurus, of which B. M. No. 96.1.7.1 is the
type. Eleven specimens of C. obscurus from the Paramo de Tama, head
of the Tachira River, Colombia and Venezuela. Collected by W. H.
Osgood in February and March, 1911, and referred to by him, with
the promise of a subsequent paper on the subject, in the account of
his' expedition.1 Now in the Field Museum of Natural History,
Chicago. Finally the series of Orolestes inca from Peru.
When describing Goenolestes obscurus I distinguished it from G.
fuliginosus mainly by size, but as Tomes's type proved to be young,
there was until recently nothing to show whether the two species
were or were not distinct. Now, however, I am able to state, on the
evidence afforded by Mr. Goodfellow's specimens, that G. obscurus
has rather larger teeth than C. fuliginosus (first three molariform
teeth 6.2 instead of 5.5 or less) ; that it is grayer and less brown in
1 Field Mus. Nat. Hist, Publ., vol. 10, p. 38, 1912.

no. 2333. MAMMALIA COLLECTED IN PERU BY HELLER— THOMAS. 247
color above, exactly as in Orolestes inca, -washed with grayish white
below, instead of brown; and, finally, that it is distinguished from
both the other members of the family by the anteorbital vacuities
being filled in with bone. In the young specimen, the type, there is
still a narrow unossified cleft between the outer corners of the nasals
and the maxillae, but in the adult specimen even this is almost com
pletely closed up.
The very great sexual difference in size between our two adult speci-
specimens of G. obscurus is noteworthy (male skull 36.3, female 32.5),
this being considerably greater than in Orolestes, but whether it is
constant I do not know, nor have I material to state what is the cor
responding difference in C. fuliginosus
In accordance with the latest conclusions of the> paleontologists
who have written on the subject, I am now quite prepared to admit
that Coenolestes and its allies should be reckoned as more related
to the Polyprotodonts than to the Diprotodonts.
60. DIDELPHIS MARSUPIALIS ETENSIS Allen.
A young male from Santa Ana, 3,000 feet (No. 194373).
61. DIDELPHIS PARAGUAYENSIS PERNIGRA Allen.
Seven specimens as follows :
Chospyoc, 10,000 feet, 2 (Nos. 194358-9).
Torontoy, 2 (Nos. 194360-1).
Machu Picchu, 3 (Nos. 194367-8, 194370).
While most of the specimens hitherto obtained in southern and
southeastern Peru have been in the black phase, these specimens,
curiously enough, are with one exception in the gray phase, with the
dorsal piles white. They thus exactly resemble average specimens
of D. p. andina, the opossum of Ecuador and North Peru.
62. METACHIRUS NUDICAUDATUS TSCHUDII Allen.
Adult female, Rio Cosireni, 3,000 feet (No. 194376).
63. PHILANDER LANIGER ORNATUS Tschudi.
Adult female, Rio Comberciato, 2,000 feet (No. 194375).
With well-marked postauricular gray lines, these, like the median
patch on the foreback, appearing to be individually variable. Of
three specimens from the Upper MaranOn, one has them and two
have not. [MARMOSA RAPPOSA Thomas.]
[A female and four young in the British Museum from Vilcanota
River, Cuzco. Nos. 98.11.16.13-17, the adult the type. O. Garlepp.]

248 PROCEEDINGS OF THE NATIONAL MUSEUM. T01- 58-
64. MARM0SA IMP A VIDA Tschudi.
Adult male, Torontoy, 8,000 feet (No. 194378).
The examination of this specimen, with its really white under-
surf ace, has made me revise the determination of our small Peruvian
Marmosae. This character had not previously been observed in any
Peruvian species, but now Mr. Heller's specimen corresponds so
closely with Tschudi's description, both in this and other respects,
that it should certainly be regarded as impavida. In consequence,
the specimens from Chanchamayo and Marcapata that I had pre
viously called impavida, as also those from Yurimaguas, so named
by Mr. Osgood with my connivance, need redetermination. On the
whole it appears to me that they may suitably be called M. noctivaga
Tschudi, a form which I had wrongly assigned to M. cinerea, but
whose type I have since seen in Neuchatel and have taken a measure
ment of its teeth, which closely correspond with those of the Chan
chamayo examples.
The skull and teeth of M. impavida are markedly smaller than
those of noctivaga, agreeing in fact very nearly with those of M.
quichua, the latter being distinguishable mainly by its cream-buffy
throat and chest and broadly slate-based belly hairs with buffy fawn
tips. Even on the white uiidersurface of Mr. Heller's specimen there is
an unsymmetrical area on the side of the chest where the hairs are
slaty gray at base, but this is obviously an individual variation.
[MARMOSA QUICHUA ThomasJ
[A specimen in the British Museum from Ocobamba, Cuzco. No.
98.11.6:18. Type. Collected by O. Garlepp.]
65. PERAMYS PERUVIANUS Osgood.
Two males from Ocobamba Valley, 9,100 feet (Nos. 194379-80).
These two specimens, caught in the same place on successive days,
differ remarkably in color, but agree in so many essential characters
that they must, I think, belong to the same species. No. 194379 is
grayish above, anteriorily, while 194380 is more uniformly brown,
and very like P. adustus; but the former is very old, with worn
teeth, and the grayness is probably due to senility. Then also 194379
has the buffy abdominal patches described in the type, while, like
P. adustus, 194380 is without them. This again, however, may be
an age characteristic — a point which further material can alone
elucidate. The British Museum possesses no Peramys from Peru, the two de-
examnlt fT^* described *>J Osgood being the only Peruvian
examples of the genus on record.

no. 2333. MAMMALIA COLLECTED IN PERU BY HELLER— THOMAS. 249
The skulls of both the present specimens are unfortunately broken
to pieces, and it is only possible just to compare the size and wear of
the molar teeth. EXPLANATION OF PLATES.
Plate 14.
(All figures approximately natural size.).
Fig. 1. Skull of Holoohilus incarum Thomas. No. 194915, U.S.N.M. Type.
See p. 226.
2. Skull of Oryzomys (Microryzomys) aurillus Thomas. No. 194796,
U.S.N.M. Type. See p. 228.
3 Skull of Hesperomys frida Thomas. No. 194779, U.S.N.M. Type. See
p. 230.
4 Skull of Thomasomys notatus Thomas. No. 194548, U.S.N.M. Type.
See p. 233.
5 Skull of Thomasomys gracilis Thomas No. 194816, U.S.N.M. Type. See
p. 234. Plate 15.
(All figures approximately natural size.)
Fig. 1. Skull of Thomasomys daphne Thomas. No. 194902, U.S.N.M. Type.
See p. 235.
2. Skull of Akodon surdus Thomas. No. 194663, U.S.N.M. Type. See
p. 236.
3. Skull of Chroeomys inornatus Thomas. No. 194685, U.S.N.M. Type.
See p. 238.
4. Skull of Microxus torques Thomas. No. 194607, U.S.N.M. Type. See
p. 239.
5. Skull of Orolestes inca Thomas. No. 194401, U.S.N.M. Type. See p.
244.

U. S. NATIONAL MUSEUM

PROCEEDINGS, VOL. 58 PL. 14

I. HOLOCHILUS INCARUM.

2. Oryzomys aurillus.

3. Hesperomys frida.

4. Thomasomys notatus.

5. Thomasomys gracilis.
SKULLS OF PERUVIAN MAMMALS.
For explanation of plate sec paqe 249.

U. S. NATIONAL MUSEUM

KKUUttmnnjo, yui- «o

I. Thomasomys daphne.

2. Akodon surdus.

3. Chroeomys inornatus.

4. Microxus torques.

5. Orolestes inca.
SKULLS OF PERUVIAN MAMMALS.
FOR EXPLANATION OF PLATE SEE PAQE 249