254 -Mr. O. Thomas on 



others by its dark-coloured throat, the whitish belly colour 

 usually ruiuiing right up to the chin. Its nearest ally is 

 probably P. hrevicauda, Giiuth., with which it agrees iu the 

 suppression of the parietal ridges, but that animal has a 

 buff)'" underside, nearly uniform from chin to anus^ and its 

 pahital foramina are shorter and have less developed 

 posterior lips. 



Proechimys semispinosus calidlor, subsp. n. 



A rufous lowland representative of true semispinosufi. 



Essential characters of true semispinosus^ Tomes *, but 

 the general colour dark rich rufous (nearest to ''cinnamon- 

 rufous ")^ heavily blackened on the dorsal area. Sides clearer 

 cinnamon-rufous, varying in some specimens towards butfy. 

 Under surface and inner side of limbs pure, sharply defined 

 white. Hands and feet brown. Tail well haired, black 

 above, whitish below. 



Skull quite as in true semispinosus. 



Dimensions of the type (measured in flesh) : — 



Head and body 249 mm.; tail 168; hind foot 48; 

 ear 26. 



Skull : greatest length 58 ; condylo-incisive length 49 ; 

 greatest breadth 28*5; nasals 22 ; interorbital breadth 13'6 ; 

 palatilar length 20; palatal foramina 4*6; upper molar 

 series 9. 



Hah. San Javier, Lower Cachavi E,., N.W. Ecuador. 

 Alt. 60'. 



Type. Adult female. B.M. no. 1. 3. 19. 30. Original 

 number 10. Collected 6th May, 1900, by Messrs. Flemming 

 and Miketta. Eight specimens. 



On Specimens referred to Kerodon boliviensisj Waterli. 



Putting aside the Argentine Cavies representing Kerodon 

 hucohlepharus, Burm. (with range from Salta to Mendoza), 

 the Bolivian and Peruvian specimens hitherto referred to 

 Waterhouse's K. holiviensis appear to belong to three species, 

 distinguishable largely by the sizes of their bullae. 



But tlie matter is complicated by the fact that among the 

 original series of holiviensis received by the Museum from 

 Mr. Bridges, more than one of these species appears to be 

 represented, while in hardly any of them have the bulhe 

 been preserved. Fortunately in one specimen a perfect bulla 

 remains, and this example — no. 45. 11. 18. 22, skull 518 a — 



* Type now in the Museum collection, no. 7. 1. 1. 173. 



