318 PROCEEDINGS OF THE ACADEMY OF 



denly clown to the nape. The upper corners of the head, upon 

 which the ears rest, are elevated and wide apart; the top of the head 

 has in general a triangular shape, tapering from each ear to the 

 snout with but slight swelling in the orbital region, and is quite 

 flat across, with the most gentle longitudinal curve in the frontal 

 region, and nearly straight nasal profile. The muzzle is acuminate, 

 and much produced, appearing longer still in consequence of the 

 remarkably small retreating chin. The muzzle is entirely hairy, 

 excepting a small nasal pad ; this shows a median depression, but 

 there is no cleft of the upper lip, the whole of which is thickly 

 clothed with stout hairs, that form a dense fringe drooping over 

 and concealing the superior incisors. The low 7 er lip is thickened 

 and densely hairy ; and there is also a hairy commissure of the 

 upper lip behind the superior incisors, so that these teeth are shut 

 out of the true (mucous-lined) buccal cavity. For the rest, the 

 lips seem to come together vertically instead of horizon tall}', 

 closing the oral aperture sidew r ays, though of course the buccal 

 cavity or mouth proper shuts as in ordinary mammals. All this 

 is essentially the same as in the Geomyidse ; and further, as in 

 these last, there is a great pouch on each side of the head, entirely 

 disconnected with the mouth, formed of a duplication of ordinaiy 

 integument, hairy throughout. These sacs will admit the first 

 joint of one's little finger ; they run the whole length of the head, 

 but not beyond to the shoulder. In relative capacit}^ the} r about 

 equal the least developed pouches of Geomyidse those of G. his- 

 pidus for instance. The opening is crescentic; the inner limb of 

 the semilune being the skin of the jaws, while the outer limb is a 

 free fold or border arising on the side of the snout half way between 

 nostrils and incisors and a little back of both, and curving loosely 

 around to the side of the under jaw near its middle. 



The whiskers are extremelj r numerous, and some of them are 

 very long. A bunch of short fine ones springs from the extremity 

 of the snout, on each side, by insensible lengthening of the fringe 

 of hairs that clothe the upper lip. Others grow in the usual site, 

 and the longest of these usually exceed half the total length of the 

 body. There are other long slender bristly hairs in weak clumps 

 about the eyes and ears, and a bunch of short antrorse bristles 

 springs from the chin. The eyes are large and prominent, in life 

 remarkably soft and expressive, in striking contrast to the little 

 piggish peepers of the Geomyidse; in consequence of the production 



