176 U. Ss. P. R. R. EXP. AND SURVEYS—ZOOLOGY—GENERAL REPORT, 
List of specimens. 
Efe. : From tip of nose to—| Tail to end of— = 
3 35 5p Locality. Whence obtained. | Nature of spe- a Collected by— 
3 1 oa | a cimen. = 
f | = < 
3 |s°e a ia 
= 5 Fd Occip. Tail. | Verteb.| Hairs. | & 
oan) nD A 
| = Toma aes as TF | 
1060)) icasen|eoeese City of Mexico ........ John Potts..... ... SKID cccccesee |e vcccceses 10.40 5.60 6.70. | 1.49.) . se. cccsdenehniesaase 
200 | 1177 | ..... Ringgold Barracks ..... Maj. W. He EMOry-|. 0:0 scccdenecc|scnscccccslecceeevsselecasccen|scencescleseans John H. Olark...... 
| 
239 |...e0s © | Matamoras, Mexico..,.| Lt. D. N. Couch ..}...d0 cecsccseeelecevcevece|-ccctecseelscecteeeleceeseeslecces Dr. L. Berlandier. 
601 | 1724 O Jecceve WO cossdscus ciscaviacsan's Os occ eseves|ccslO....cceece 2.25 10,33 6.08 7.50. || occven}cooeh) | Soke eeReenee 
602] 1725] Go J.scese Osc cclcccevcscenslecevee GO. cee cvccce «rO yonaeseser 2.00 8.25 4.66 5.00 |..ccen|.cvccccscsccsevecsscns 
2320 | ..000- O Jecvece GO vewc vccceccccce|ccnces dO. sseecveees oO waccseecee 1.92 6.76 3.75 4.15 || 1.34 |eeccescunsuobuaseen 
BIDTR vees'es O jevveee GO. eecccnsececcccleocecs GOs veccescoce In alcohol...... 1.72 6.00 2.90 S16 || LES i occen cdewecncabieyes 
2322 |.....- OG) ices HOvecewaeessccecer|ssness ise ssoaeae 3160) cxcoin$ aotc| Pateonocc. 12.00: | (6275 || °6:92 | 170i) Feeeeseeeoeeeetenee 
250 say oO} | Ne033 HG cseapelelenenlees| scenes dOawdeeanewes SO memes oes 2.18 7.15 | 4.75 | 5.28 | 1.45 | ccscccsdsesenesmene 
2324 |. .c00. 20 pec WO sesectacasceres|oesses WO vecwieensmas dO secccceses 1.75 6.63 3.30 3.66 | 1.15 |. .cccccceeces: ossece 
2325 |wecees O  |ewsece GO. sccvccveccccee|sevece MO eaidinte cea GO) Sscocacocs 1,25 5.80 1.30 1.60 80 | .ccecevecssecrerenee 
PUTORIUS XANTHOGENYS. 
Yellow Cheeked Weasel. 
Mustela xanthogenys, Gray, Ann. and Mag. N. H. X{, 1843, 118.—Is. Zool. Sulphur, 1844, 31; pl. ix. 
Sp. Cu.—Similar to P. frenatus. Tail vertebre about half the length of the body; the hairs about one-eighth this length. 
Head chestnut brown, little darker than the back; the three patches on the face reddish yellow ; body chestnut brown above, 
reddish white beneath ; tip of tail black. 
This species is closely related to P. frenatus in general characteristics of tint and pattern of 
coloration. The ears are rather more acute than in P. frenatus,-and not so broad at the base. 
The toes are longer and less fully webbed ; the under surfaces of all the feet more densely furred. 
There are ten balls on the fore feet, but these are smaller than in P. frenatus; of the nine on 
the: hind feet, two or three on the soles can with difficulty be made out, owing to their being 
buried in the fur; the interspaces between all have short stiff hairs, instead of being nearly 
naked. This may, however, depend somewhat on the season. The tail, though mutilated, is 
apparently about half the length of the body. 
The upper parts and sides are of a chestnut brown color; beneath, of a dull brownish or 
rusty yellow. The chin is of a paler tint. There is a yellowish spot on the top of the muzzle 
anterior to the eye, and a patch of the same commences acutely about midway on the edge of 
the upper lip, and passes in a sub-crescentic direction behind the eye, about half way between it 
and the ear, though not getting as high as the upper edge of the latter. The whole space 
between the ear and the border just described is occupied by this color. There is a dusky spot 
on each side of the lower jaw. The upper part of the head is a little deeper in color, though far 
from having the intensity of P. frenata. The tail is like the back, dusky at the tip. 
In the arrangement of the patches on the head, this specimen differs materially from P. 
frenatus, as compared with nine specimens from Matamoras. The frontal patch is of much less 
extent, and situated considerably further in advance of—not between the eyes—but on top of 
the nose. The brown mask on the side of the head, instead of extending backward in an acute 
point for twice the length of the lower jaw nearly to the ear, and with its upper edge parallel 
with the base of the ear, as in P. frenatus, is quite abruptly truncated by the light patch, which 
is thus broader at the base, but does not extend so high up. The under parts have a good deal 
