neto South- American Mammals. 195 



Cavia boliviensis liltoralia, subsp. n. 



Fur short, Imir.s of back only about 17 milliin. in leii^^th 

 (apart from tho line clouf^ated points). General colour abovo 

 .similar on tlio 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 I'ound in 

 G. b. leucohlephara being- replaced by alternate lighter and 

 darker rings of grey ; subterminal ring biiffy, tips black. 

 Rings round eyes lighter than head, but not conspicuously so. 

 Belly dull buffy white, not sharjily defined, the bases of the 

 hairs grey. Upper surface of hands and feet bufty, 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 premaxillury processes. 

 Zygomata less widely ex])anded anteriorly. Palatal foramina 

 shorter and broader. BuUje smaller. Incisors very narrow. 



Dimensions of the type (measured in the flesh) : — 



Head and body 19y millim. ; hind foot, s. u. o5, c. u. H9 ; 

 ear 18. 



tSkull : greatest length -17 ; basilar length 38*7 ; zygo- 

 matic breadth 28 ; nasals l.VGx 6 ; iiitcrorbital breadth 9'8 ; 

 interjiarietal 5"2 X 9 ; mastoid breadth 20'5; diastema 12"."> ; 

 palatine foramina 4 X 2*3 ; length of palate from henselion 20 ; 

 length of upjier molar series 11 ; combined breadth of lower 

 incisors 2"0. 



Ilah. 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 G. bolivi- 

 ensis have now been received from different localities round 

 Lake Titicaca, collected by Messrs. Pentland, Garlepp, Kali- 

 nowski and iSimons, and these, like the original series 

 collected by Bridges, vary considerably in their general 

 colour, the whiteness, brownness, or bufliness 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 G. leuco- 

 blejihara^ 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. 



