228 Mr. G. Dollman on 



the corresponding tooth in the upper jaw ; composed of two 

 cusps, one on either side of a median groove. 



Type, Prionomys batesi. 



This genus would appear to be more nearly related to the 

 genus Dendromus than to any other of the allied genera. 

 The teeth, while resembling those of Dendromus to a certain 

 extent in their general arrangement, possess such curiously 

 shaped cusps that it is evident at once, from this character 

 alone, that the two genera are quite distinct. The general 

 appearance of the skull, with the ungrooved slanting incisors, 

 short palatal foramina, and great breadth of the brain-case 

 and zygoma, is quite unlike that of any other member o£ the 

 Dendromyinse. 



Externally the animal exhibits a series of characters quite 

 as distinct as those of the skull. Though resembling Den- 

 dromus in the possession of a long prehensile tail, it is readily 

 distinguished by the occurrence of four well-formed digits on 

 the fore feet and by the presence of comparatively small 

 simple ears. 



Prionomys batesi, sp. n. 



General appearance and size much the same as a large 

 species of the genus Dendromus. 



Ears rather small and rounded, thinly clad on both surfaces 

 with short dark hairs. Feet as described above. Fur soft 

 and rather short, measuring 4 or 5 mm. in length on the 

 back. Whiskers long and fairly numerous, with black bases 

 and greyish tips. General colour of upper surface pale 

 chocolate (between chocolate no. 2 and otter-brown no. 4, 

 1 Repertoire de Couleurs '), paling on the flanks and passing 

 almost imperceptibly into the greyish tint of the ventral 

 surface. Face between eyes rather paler than rest of upper 

 parts ; sides of face below eyes lighter and washed with 

 pinkish buff. Eyes surrounded by narrow blackish rings. 

 Individual hairs of body dark slaty grey with chocolate-buff 

 tips. Back of hands and feet covered with very short 

 whitish hairs, a few darker hairs on the metacarpal and meta- 

 tarsal regions. Entire underparts grey, washed with pale 

 pinkish buff ; hairs with pale slate-grey bases and long 

 pinkish-buff tips. Tail blackish brown, thinly clad with a 

 number of minute brownish hairs, appearing at first sight 

 almost naked. Apical portion of upperside of tail devoid of 

 hair, probably prehensile, as in Dendromus. Lower surface 

 of tail similar to upper, except that the minute hairs extend 

 right to the tip. 



