new South-American Mammals. 195 
Cavia boliviensis littoralis, subsp. n. 
Fur short, hairs of back only about 17 millim. in length 
(apart from the fine elongated points). General colour above 
similar on the whole to the more northern subspecies, but 
more finely speckled and also less yellow than in most 
specimens of the typical form. Hairs of back indistinctly 
annulated to their bases, the paler slaty bases found in 
C. b. leucoblephara being replaced by alternate lighter and 
darker rings of grey; subterminal ring buffy, tips black. 
Rings round eyes lighter than head, but not conspicuously so. 
Belly dull buffy white, not sharply defined, the bases of the 
hairs grey. Upper surface of hands and feet buffy, becoming 
paler terminally. 
Skull shaped as in the true C. boliviensis, but smaller, 
although this may be due to immaturity. Nasals narrower 
and ending opposite the ends of the premaxillary processes. 
Zygomata less widely expanded anteriorly. Palatal foramina 
shorter and broader. Bullee smaller. Incisors very narrow. 
Dimensions of the type (measured in the flesh) :— 
Head and body 199 millim. ; hind foot, s. u. 35, ce u. 39; 
ear 18. 
Skull: greatest length 47; basilar length 38:7; zygo- 
matic breadth 28; nasals 15°6x 63; interorbital breadth 9°8 ; 
interparietal 5°2x9; mastoid breadth 20°5; diastema 12°5 ; 
palatine foramina 4 x 2°33 length of palate from henselion 20 ; 
length of upper molar series 11; combined breadth of lower 
incisors 2°0. 
Hab. Bahia Blanca, Argentina. 
Type. Female. B.M. no. 0. 8.5.7. Collected 29th Sep- 
tember, 1896, by Mr. W. Jex. 
A considerable number of specimens of the true C. bolivi- 
ensis have now been received from: different localities round 
Lake Titicaca, collected by Messrs. Pentland, Garlepp, Kali- 
nowski and Simons, and these, like the original series 
collected by Bridges, vary considerably in their general 
colour, the whiteness, brownness, or buffiness of their bellies, 
and even more strikingly in the shape of their nasals. How- 
ever, none of them agree in the shortness of their fur, the 
fine speckling of the back, and the annulation of the bases of 
the dorsal hairs with the Cavy from Bahia Blanca. Speci- 
mens from the intermediate localities, representing C. leuco- 
blephara, Burm., agree in these characters more with the 
Titicacan animal. 
Owing to the difficulty in determining the age of Cavies, I 
am not sure as to the exact age of the specimen, but think it 
would have attained rather larger dimensions. 
