498 Mr. O. Thomas on small Mammals 



by the absence of the prominent white patch on the chin, a 

 character generally fairly constant. 



Tiie two species form rather a special group of the genus, 

 but without specimens with less worn dentition it is difficult 

 to make sure of their true relationship. 



12. Ctenomys hnighti^ sp. n. 



(?. 336, 338, 357 ; ? . 328, 332, 335,339,340, 341, 345, 

 360, 362. 



Allied to C. hudini, Thos., of Jujuy. 



Size about as in budini, the skulls of the males a little 

 larger than male budini, but the females about the same. 

 Colour above nearly as in that animal, or a little darker, 

 rather paler than " Mars brown " ; flanks, especially poste- 

 riorly, distinctly clearer buffy, no such clearing of the general 

 grizzled colour being present in hudini ; under surface 

 uniform, without collar across throat, the whole distinctly 

 more ochraceous than in budini, the ends of the hairs 

 ''cinnamon-buff" or "pinkish cinnamon." Muzzle, both on 

 top and sides of nose and tip of chin, blackish — ^^no darkening 

 being present in budini. Tail slightly longer than in budini, 

 the longest in four specimens of tliat species 70 mm., while in 

 knighti it ranges from 73 to 84 mm. 



Skull of about the same general shape as in budini, or 

 slightly more elongate, nasals rather narrower. Parietal 

 region without trace of separate interparietals, even in the 

 youngest specimen, these bones being present in all four 

 examples of budini. Palatine foramina longer, in a groove 

 leading forward and enclosing the incisive fissures ; in budini 

 the foramina end abruptly on the general surface of the 

 palate and the fissures are quite distinct from them. Bullse 

 of the same general shape, but rather larger, and, as viewed 

 from behind, their smooth postero-superior portion is much 

 more cons))icuous owing to its being less covered over by the 

 plastering bones of the occipital series. 



Teeth as in C. budiniy except that m^ has a more obliquely 

 elongate section at all ages. 



Dimensions of the type (male) and of an adult female 

 (no. 340) :— 



Head and body 203, 180 mm.; tail 82, 74; hind foot 

 36, 30 ; ear 7, 7. 



Skull: greatest median length 49*5, 44; condylo-incisive 



