DESCRIPTION OF A NEW MOUSE 
FROM NEW MEXICO. 
Hesftero?nys ( Vesperinius) Anthonyi sp. nov. 
By Uiv. C. HART MERRIAM. 
[From the Proceedings of the Biological Society of Washington, Vol. IV, 1886-’87.] 
Separates issued April 16, 1887. 
BIBSON BROS.HtS.NAM From the Proceedings of the Biological Society of Washington, Yol. IV, 1886-7. 
Extras printed April 15, 1887. 
DESCRIPTION OF A NEW MOUSE FROM NEW 
MEXICO. 
Hcsperomys ( Vesperimus') Anthonyi sp. nov. 
By Dr. C. Hart Merriam. 
(Read March 19, 1887). 
During the spring and summer of 1886, Mr. A. W. Anthony, 
of Denver, Colorado, made his headquarters at Camp Apache, 
Grant county, New Mexico (about lat. 310 20 ). Camp Apache 
is in a hot desert region in the extreme southwestern corner of 
the Territory, and only about four miles from the Mexican 
boundary. 
The following extract from one of Mr. Anthony’s letters 
sufficiently describes the region. He writes: “You can form 
some idea of my location when I tell you that our nearest 
water is a very small spring nine miles across the valley, 
from which all our water is carried in wagons. The only 
trees within forty miles are a few very small stunted cedars 
and oaks. The only other vegetation consists of cacti and 
other plants characteristic of these hot dry deserts.” 
While in this region Mr. Anthony made a valuable collec- 
tion of mammals, which he has very kindly presented to me. 
Among other things of interest it contains five specimens of a 
pretty little mouse, hitherto unknown in the United States, 
which I believe to be undescribed, and which, therefore, I 
take pleasure in dedicating to its discoverer. In coloration, 
proportions, and cranial characters this mouse differs so rad- 2 
BIOLOGICAL SOCIETY OF WASHINGTON. 
ically from all previously known species, that comparison 
with others is unnecessary. Unfortunately, nothing is known 
of its habits. It may be distinguished from its congeners by 
the following diagnosis : 
HESPEROMYS (VESPERIMUS) ANTHONYI sp. nov. 
Type No , male ad., Merriam Collection. 
J 2841 
Size, small ; tail considerably longer than head and body ; 
ears large and scant haired ; whiskers long, reaching past 
shoulders. Soles naked, 6 tuberculate ; palms 5 tuberculate ; 
thumb armed with a blunt nail. 
Coi.or.—Upper parts from nose to tail, uniform clear ash- 
gray, more or less darkened by black-tipped hairs; sides 
bright buffy-fulvous ; under parts white, the plumbeous basal 
portion of the hairs showing through on the chin and throat, 
which are thinly clothed with rather short hairs; bell)' 
strongly washed with salmon, which may be due to earth-* 
staining. Pelage soft. The fur covering the breast, abdo- 
men, and flanks is very much more dense than that of the 
rest of the body, from which it may be distinguished at a 
glance. In fact, on the sides it forms well-marked flank 
patches or tufts. Possibly this character may be seasonal ; 
if not, it is very remarkable. In the young the belly is pure 
white, and the bufty-fulvous flank patches are not apparent. 
The material at hand consists of five skins and skulls, col- 
lected in April and May. All are males. Nos. 2332 and 
2335 are immature, though the latter is full grown. The 
skins were prepared with unusual care, and consequently 
afford measurements of approximate accuracy. Moreover, Mr. 
Anthony recorded the total length of each before skinning. DESCRIPTION OF A NEW MOUSE. 
3 
Table of Measurements of five Specimens of Hesperomys Anthonyi collected 
at Camp Apache, Grant County, New Mexico, by A. W. Anthony. 
(Measurements in millimeters'). 
Sex 
Measured in 
the Flesh.* 
Measured 
FROM 
THE DRY SKIN. 
Skin 
Skull 
Head 
and 
body. 
Tail, to end of 
Height 
No. 
No. 
Age. 
Total lengtli. 
Total 
lengtli. 
Verte- 
brae. 
Hairs. 
Hind 
foot. 
of Ear 
from 
crown. 
Date. 
•2149 
2675 
J'ad 
165 
144 
63 
80 
81.5 
18.5 
12. 
Apr. 12,1886. 
2332 
2840 
cJ'im. 
162 
145 
62 
82 
83.5 
18.5 
11. 
“ 5, “ 
2333 
2841 
d' ad 
168 
145 
63 
81 
82.5 
19.5 
12. 
May 10, “ 
2334 
2842 
C? ad. 
165 
150 
66 
83 
85. 
19.5 
12. 
“ “ “ 
2335 
2843 
cfim. 
162 
139 
64 
74 
75. 
19. 
10. 
U 44 44 
Cranial Characters.—The skull, compared with that of 
H. leucopus, is short, broad, and flat. The incisor foramina 
reach past the anterior plane of the first molar. The nasals are 
short and do not extend so far posteriorly as the premaxillaries. 
Excluding skull No. 2840, which is not full grown, the close 
agreement in cranial measurements is remarkable. 
Cranial Measurements. 
No. 
2840 
No. 
2841 
No. 
2842 
No. 
2843 
fj'im. 
d ad. 
d ad. 
d 
Basilar length (from one of the occipital condyles to posterior 
edge of alveola of incisor of same side) 
18.9 
20. 
20.3 
20.4 
Basilar length of Hensel (from inferior lip of foramen magnum 
to posterior edge of alveola of incisor) 
16.5 
18. 
18. 
18. 
Greatest zygomatic breadth 
12.4 
12.8 
12.7 
12.1 
Interorbital constriction 
3.8 
3.9 
3.7 
3.7 
Greatest length of nasal bones 
7.4 
7.8 
8.5 
8.3 
Length of upper molar series 
3.6 
3.8 
3.8 
3.8 
5 4 
5.6 
5 6* 
5 7 
11 “ post-palatal notch 
8.8 
9.5 
9.5 
9.5 
Distance between alveolae of upper molar series anteriorly 
2.5 
2.5 
2. 5 
2.5 
“ . “ “ “ “ “ “ posteriorly 
2.5 
2.5 
2.5 
2.5 
Foramen magnum to post-palatal notch 
7.4 
8. 
8. 
8.2 
Height of cranium from inferior lip of foramen magnum 
6.8 
7.3 
7. 
7. 
Fronto-palatal depth (taken at middle of molar series) 
5.8 
6.2 
6. 
5.8 
Length of mandible 
12.6 
12.9 
12.9 
13.2 
Length of under molariform series 
3.7 
3.8 
3.8 
4. 
* The apparent discrepancy between the total length as recorded by Mr. 
Anthony and that taken from the dry skin is due to the necessary stretching 
of the fresh specimens for measurement.