76 EINAR LONNBERG, MAMMALS COLLECTED IN CENTRAL AFRICA. 



length, whereas in the male they taper evenly to the posterior end. The raised lines on 

 the frontals are erect and converge rather strongly in a forward direction so that in the 

 anterior part of the frontals they are situated entirely on the upper surface, remote from 

 the lateral wall of the skull, which in the anterior part of the orbit is rounded off to- 

 wards the roof of the skull. In the female ( »emini)>?) the corresponding raised lines form 

 almost horizontal crests protruding rooflike over the lateral wall of the skull. 



The fronto -parietal suture is in the male straight and quite transverse, in the female 

 it is semicircular, but this is no doubt a variable characteristic. The shape of the inter- 

 parietal appears also to vary a great deal in this genus, as I have observed on the material 

 of G. g. kivuensis, where it is sometimes more, sometimes less broadly triangular, or even 

 somewhat rounded off on the anterior side. The relative size seems, however, to be about 

 the same within the racial limits. For this reason it may be mentioned that in the male 

 skull,, now described, the interparietal bone is comparatively very small, measuring 4,7 

 mm. in length by 6 in breadth. In the »emini » female the same dimensions are 5,8 and 

 9 mm. 



This comparison proves that, although a number of cranial dimensions are very 

 similar, or almost identical, these two specimens in other respects piresent so great dif- 

 ferences, that it is impossible to unite them within the same subspecies. There are thus 

 to be found, as far as can be understood from the present material, not only a small- 

 toothed and a large-toothed race of light-bellied Cricetomys-ioTms in the same district 

 at Masisi, but there are even two different large-toothed forms. The great faculty of 

 variation displayed by the genus Gricetomys is illustrated by these facts. Although I do 

 not think that this specimen can be referred to any described subspecies I refrain for the 

 present to name it, because only one specimen is available. 



Gricetomys gambianus proparator Wroughton. 



1 ? from Beni collected V, 1913. 



This specimen agrees on the whole very well with Wkoughton's description with 

 regard to colour and cranial characteristics. The differences may chiefly be due to in- 

 dividual, or perhaps seasonal differences. These differences are as follows. The fur is 

 not 16, but hardly more than 12—13 mm. long, single hairs perhaps a little longer. It 

 is grey not greyish white at the base. The hind feet are not entirely white, but brown 

 in the middle of the upper side. The length of the hind foot of this dry specimen is not 

 quite 68 mm. 



The cranial measurements do not present any difficulties for the identification. 



Greatest length of skull 76 7 xam. 



Basilar » » » g^ „ 



Condyloincisive length of skull 72 » 



Zygomatic breadth of skull 32 5 » 



Nasals 312 „ 



Palatal foramina ... 8 » 



Diastema 24 » 



Interorbital breadth .. U3» 



Upper molar series 1 1 3 » 



Greatest breadth ot m' . . . . 3 4 » 



