544 RODENTIA 



naked, its surface almost entirely occupied by three tubercular 

 masses, separated by narrow furrows ; anterior pad at bases of 

 digits obscurely trilobed ; posterior pads roundish, the outer 

 larger than the inner. Hind foot much like fore foot, but 

 median claws shorter and hallux better developed than thumb, 

 its claw differing from those of other digits in its smaller size 

 only ; transverse groove separating trilobed tubercular mass at 

 base of digits from posterior mass less distinct than in front 

 foot ; posterior mass single, its anterior border showing a 

 tendency to bilobation. Tail very short, completely hidden 

 in the mass of quills which arise from it. Head, neck, shoulders, 

 limbs and underparts covered with coarse grooved bristles, 

 ranging in length from 20 to 45 mm., their width usually about 

 2 mm., though those on head are more slender and hair-like, 

 and those along median line from between eyes to shoulders 

 are greatly elongated, attaining a length of 300 mm. and pro- 

 ducing a conspicuous erectile crest or mane ; posterior half of 

 back and sides thickly beset with terete quills, ranging in length 

 from 35 to 300 mm., the longest on or near median line, the 

 extremities for the most part stiff and awl-like, but occasionally 

 drawn out into a hair-like filament ; base of tail with stiff terete 

 quills like those of body ; tip bearing a cluster of about a dozen 

 highly modified quills with slender thread-like bases (about 

 20 mm.) and a hollow terminal portion 20 to 30 mm. long, the 

 hollow part compressed at its base but becoming terete distally ; 

 whiskers stiff and long, extending to shoulders when laid back ; 

 throughout the body there is a sparse growth of coarse hairs 

 among the spines and quills, these hairs most numerous and 

 longest on posterior half of back, where they reach a length of 

 100 to 150 mm. 



Colour. — Underparts, sides and legs blackish brown, the 

 bristles becoming horn-colour at base ; head, neck and shoulders 

 drab, many of the bristles in mane white or whitish ; whiskers 

 black ; quills on back, sides- and tail blackish horn-colour, with 

 whitish terminal area 50 to 80 mm. long, and one to three 

 whitish annulations, each about 10 mm. in length, the general 

 effect of the quilled region black conspicuously spotted and 

 streaked with white. 



Skull. — In general appearance the skull differs strikingly 

 from that of other European rodents in the great depth and 

 width of the facial poi-tion (post-lachrymal width about equal to 

 depth through same region, and fully one-half basilar length ; 

 occipital depth only about two-thirds that at middle of palate), 

 the unusual area occupied by the nasal bones (posterior margin 

 of nasals near glenoid level ; greatest combined breadth of 

 nasals, in lachrymal region, half or two-thirds their length, and 

 nearly equal to depth at front of tooth-rows), and the very 

 slender, weak anterior extremity of rostrum. Dorsal profile 

 evenly convex from front of nasals to about their posterior 



