158 Mr. 0. Thomas on 



greyer and more or less intermediate between tliis subspecies 

 and the next ; they are, however, all immature. 



Cavia tschudii pallid lor, subs p. n. 



Similar in general cliaracters to tschudii, but colour mucli 

 lighter, the pale rings on the hairs a paler buffy, and the 

 under surface a pale creamy buff approaching- whitish. 

 Colhir a paler grey. Hands and feet buflfy whitish, a little 

 browner proxiinally. 



Skull as in tschudii. 



Dimensions of the type (measured in flesh) : — 



Head and body 242 mm. ; hind foot 24 ; ear 29. 



Skull : greatest length 59'5 ; condylo-incisive length 54 ; 

 zygomatic breadth 33*5; nasals 203 X 8-7 ; diastema 16"6 ; 

 bulla 10"2 x8 ; upper tooth-row 14. 



Hub. Arequi[)a. Type from 2500 m. 



2'i/pe. AdulL male. B.M. no. 0. 10. 1. 85. Original num- 

 ber 1023. Collected 31st May, 1900, by P. O. Simons. 

 Presented by Oldfield Thomas. Six specimens. 



Distinguished from tschudii by its lighter coloration 

 throughout. 



Cavia nana, sp. n. 



A pigmy cavy, conspicuously smaller than any other 

 species of the group. 



Size very small, skull-length only about 52 mm. Colour 

 about as in G. tschudii pallidior, the light rings on the hairs 

 buffy or pale cinnamon ; no darkening along the median 

 area of the back. Under surface creamy whitish, the grey 

 collar well marked. Hands and feet pale bi'own. 



Skull about as in C. tschudii, but conspicuously smaller. 

 Bullae especially small. 



Dimensions of the type (measured in flesh) : — 



Head and body 215 mm. ; hind foot 38 ; ear 23. 



Skull : greatest upper length 52 ; condylo-incisive lengtli 

 47; greatest breadth 29-5; nasals 17*5 X 7*5 ; interorbital 

 breadth 10"5 ; breadth of brain-case 22 ; diastema 13*7 ; 

 bulla 9*5 X 7'5 ; upper molar series, crowns 11*8, alveoli 12"5. 



Htib. Highlands of Bolivia. Type from Chiiluuniiii, 

 Yuno-as, 2000 m. Another specimen trom the Desaguadero 

 River {J. B. Pentland). 



Type. Adult female. B.M. no. 1. 6. 7. 59. Original num- 

 ber 1363. Collected 16th February, 1901, by Perry O. 

 Simons. Presented by Oldfield Thomas. Four specimens 

 in all. 



