1855.] from the Somali country. 295 



on that side, as well as the rapidity of the motion, were very 

 remarkable." The muzzle is completely furred ; and the rudimentary 

 or short tail is furnished with long hair (as in the Schtridje). The 

 rodential tusks are narrow and rounded ; and in Ctenodactylus 

 there are only three molars on each side above and below, and which 

 are surrounded with enamel ; the upper having one deep indenta- 

 tion externally, the lower being indented on both sides. In our 

 new genus there is a small and simple fourth molar anteriorly above 

 and below ; and the next to it above is smaller than the third and 

 fourth, and seems to have no distinct indentation (the molars being, 

 however, much worn away by attrition in the specimen examined). 

 The lower jaw of Pectinator is very remarkable for shewing no 

 indication even of a coronoid process ; a fact not mentioned by Mr. 

 Tarrell in his description of the anatomy of Ctenodactylus. The 

 condyle is small, and articulates on a level with the crowns of the 

 molars. The auditory bullae are remarkably large, and are seen 

 from above (as in Chinchilla). — The ant-orbital foramen is large. 

 Palate contracted, narrowing to the front ; and the post-palatal 

 emargination is continued forward to a line with the middle of the 

 last molar. Externally, Pectinator is distinguished from Cteno- 

 dactylits by having the tail and ear-conch well developed ; a smaller 

 eye ; and apparently a general adaptation for more diurnal and less 

 fossorial habits. The eyes are scarcely so large as in a common 

 Eat. The auricles are broadly ovoid, sub-nude, with a fringe of 

 whitish hairs on their anterior margin, and a patch of dense whitish 

 fur at base on their outer surface. Length of P. Spekei, from nose 

 to base of tail, about 6 in. ; and tail probably 2|- in., or with hair 

 Si in. Tarse with toes If in. Auricle (measured posteriorly) I in. 

 The skull measures 1-f- in. in length, and 1^\ in. in greatest breadth 

 (at the zygomata posteriorly) ; between the orbits somewhat exceed- 

 ing \ in. Fur soft and moderately long, of a sandy grey-brown 

 colour, slightly washed with rufous especially on the crown ; the 

 basal half of the piles pale dusky : at the nates, the fur is more 

 dense and woolly, and rufescent-whitish or pale isabelline : the 

 moustaches are, chiefly black, and the longest of them measure 

 about 3 in : the hairs upon the tail are shorter towards its base, 

 then lengthened as in the Squirrels; these long hairs being of a 



