KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 58. NIO 2. 



77 



The fact that the premaxillary sutiire cuts the palatal foramina at their posterior 

 extremity appears to be a good characteristic, as it is not found in any of the other speci- 

 mens of the present collection. 



Cricetomys microtis n. sp. 



2 ?? from Masisi, Febr. 1913. 



A dark-bellied Giant Rat with large skull and medium-sized molars. 



Colour on the back very dark brown, similar to Dauthénay's »warm sepia » Rép. 

 de Coul. 305, 4). The fur is dense, rather harsh; on the posterior back, where it is longest, 

 the average length is 15 and many hairs even 17 mm. It is dark grey at the base. To- 

 wards the sides the colour is more greyish brown, because påle »snuff brown» (Rép. de 

 Coul. 303, 1 ) hairs are mixed with dark brown, the latter become graduall}^ less numerous 

 on the flanks so that the colour there is lighter greyish brown. Thore is no line of demar- 

 cation towards the under side, which is grey with whitish tips to the hairs. Hands and feet 

 dark brown, »warm sepia» in the middle, somewhat paler on the sides, and on the toes 

 and fingers. Only the distal third of the tail light coloured. On the upper lip behind the 

 black vibrissse is a greyish spöt. 



Head and body of an adult female about 42 cm. (measurcd on the dry specimen); 

 tail about 38 cm.; hind foot (dry) about 70 mm.; ear (softened and stretched to natural 

 shape!) 25 mm. 



The other female has a somewhat more worn and bleached pclagc, and it is there- 

 fore partly paler exccpt where the new hairs are developed. 



The dimensions of two skulls both of fully adult females are as follows: 



Skull: Greatest length 



Condylobasal length . . . 

 Condyloinsive length . . 

 Zygomatic breadth . . . 



Nasals 



Least interorhital breadth 



Diastema 



Palatal foramina .... 

 Upper molar series . . . 

 Breadth of m 1 



Greatest breadth of palate measured out- 

 side m l 



Height of skull at anterior end of palatal 

 foramina 



—* 

 o" 



9 



77 mm. 



74 mm. 



73.5 » 



71,2 » 



71,3 , 



09,6 • 



34,4 » 



32,7 » 



32,3 » 



29,6 » 



10,3 » 



10,5 » 



24 » 



25,n » 



9,1 » 



9 » 



11,5 » 



1 0,5 » 



3,5 » 



3,6 » 



14 » 



13,7 » 



14 » 



13,8 » 



In most respects these measurements agree, but there are also discrepancies. The 

 longer diastema in the smaller skull corresponds with its shorter molar series. 



Another difference which is rather striking consists in the fact that the larger skull 

 in which the upper incisors are worn rather blunt, has much broader and more massive 



