102 



MONOGRAPHS OF NORTH AMERICAN KODENTIA. 



with them. The following tabic gives detailed measurements, and we arc 

 now enabled for the first time to state the length of the tail, which exceeds 

 that of the head and body very decidedly, sometimes nearly one and a half 

 inches. 



Table XXVIII. — Mcamirementa of six specimens of Hespehomys aztecus. 



HESPEROMYS (VESPERIMUS) MELANOPHRYS, Coues. 



Biack-eyed Mouse. 



t Hesperomys mexicanm, De Saussure, R. M. Z. 1860, 103, pi. ix, f. 1, la.* 

 Hesperomys (Vcsperimus) mclanophrys, Couks, Proc. Acad. Nat. Sci. Phila. 1874, 181. 



(No. 10183.) With the general aspect of a large species of the Hesperomys 

 leucopus group. Tail a little longer than the head and body together, slender, 



* " Velutinus, griseus, murinus ; in lateribus paulum fulvescens, frequenter subferrugineus ; subtus 

 albidus, pectoreet mentofulvescentibus; pedes antici albidi ; auricula) perrnagnre ; cauda corpore loDgior ; 

 mystaces elongati. 



''Intermediate in size between M. musculus and M. rattus. Pelage soft and velvety. Head conic, 

 lengtbened ; lip cleft to tbe nose ; muzzle hairy except the septum. Ears very large and broad, but higher 

 than wide, rounded, but with the upper margin a little angular. Tail long, nearly equal to the head and 

 bodu together, but sometimes only exceeding the body alone. Feet ('pattes' — more likely meaning limbs here) 

 very long, especially the hinder, the animal standing high. Color, dark brownish mouse-gray ('gris de 

 souris brun-uoiratre '), with a slight silvery shade on the back, the very tips of the hairs being yellowish- 

 gray ; head not quite so dark ; cheeks rusty-gray ; the yellowish always stronger on the flanks. Feet, 

 externally yellowish-gray (gris-fauve). Lips and chin pale yellowish-gray, and entire under parts gray- 

 ish-white, apparently plumbeous, because the slaty roots of the hairs show through; the white distinctly 

 separated from the color of the flanks. Breast and front of the shoulder washed with yellow. Fore feet 

 white, or grayish ; the hinder brown, with the ends of the toes white. Ears apparently naked, but covered 

 with short close hairs. Tail scaly, slightly hairy, black above, white below. Whiskers blackish, very 

 long, reaching to or beyond the shoulders. 



"Some individuals are yellower than as above; the sides becoming ferrugineous, strongly marked 

 on the flanks at the liue of separation between itself, the white of the belly here becoming almost pale 

 orange. Sides and under surface of the head, as well as the shoulder and breast, strongly washed wilh 

 rusty-yellow. In other specimens, on the contrary, the rusty color is not very evident. 



" Length of one specimen, about 4 2 V, with tail 4J; of another, about 4, with tail 3$; hind foot slightly 

 over one inch." 



The foregoing is M. Do Saussure's diagnosis, with an abridged translation of his further descrip- 

 tion ; tbe chief points of discrepancy, as compared with our specimens of melanojihrys, being italicized. 

 It is inserted for convenience of comparison. 



