286 Mr. M. A. C. Hinton on 



believe that these forms represent several perfectly distinct 

 species. It is difficult to compare skulls of poensis, dolichops, 

 and emini without coming to such a conclusion. Far more 

 material is needed, however, before any attempt to work 

 out the relationships can succeed. On the present occasion 

 I have to describe two new forms : one from the southern 

 part of the Belgian Congo, best treated as a subspecies of 

 C. emini, Wroughton ; the other from the island of Zanzibar, 

 provisionally accorded full specific rank. 



Cricetomys emini sanctus, subsp. n. 



Type. — An adult male (teeth more than half-worn) 

 collected at Inkongo, Sankuru, on August 27, 1912, by 

 Mr. H. Wilson ; B.M. 13. 4. 7. 5. No other specimen 

 known. 



Description. — Compared with typical G. emini, this form 

 differs in having much shorter and thinner, though equally 

 sleek fur, and more importantly in its much paler coloration 

 and smaller size. 



The back is a light brown approaching clay-colour, while 

 the flanks are still lighter ; underparts pure white. The ears 

 and a stripe extending forwards between the eyes dusky ; 

 owing to the pallid dorsal coloration the ears are more 

 strikingly contrasted with the pale cheeks and surrounding 

 parts than in typical emini. The feet are brown, practically 

 concolor with the back. The white of the tail occupies 

 rather more than the terminal third. 



Apart from its smaller size the skull differs from that of 

 typical emini only in having relatively shorter palatal 

 foramina • their length amounts to 9*8 °/ or " the condylo- 

 basal length instead of 11*7—13*4 °/ as in true emini. 



Collector's measurements. — Head and body 297 ram. ; tail 395 ; hind 

 foot 69 ; ear 38. 



Measurements of skull (with corresponding dimensions of the type of 

 emini in brackets). — Condylo-basal length 651 (74-6) ; zygomatic 

 breadth 30-8 (35-4) ; interorbital constriction 10-3 (ll - 4) ; mastoid 

 breadth 23 (26'6) ; nasals 27'9 x 9-2 (327 X 114) ; incisor to m. 3 357 

 (40'2j; diastema 221 (24 - l); length of anterior palatal foramina 64 

 (9'5) ; length of preorbital fossa for masseter medialis 11-8 (13-0) ; least 

 diameter zygomatic plate 5-6 (7) ; molar crowns 101 (11"4). 



Cricetomys cosensij sp. n. 



Type.— An adult female (B.M. 19. 6. 9. 20) collected by 

 Mr. 11. H. Swinny on the island of Zanzibar on April 2^, 

 1919 ; presented to the National Collection by Colonel Cosens. 



