CHARACTERS OF SOME HVSXRICCJIORIMJ RODEMf. 401 



..; In Ctenoii'o/s the fore feet are fos.soi-i;i]. Tlie fovir main (lif>its 

 are short and thick, and armed with long and strong daws. The 

 digital pads are not well defined from the thickened transversely- 

 grooved skin on the under side of the digits. Digits 2, 3, and 4 

 are not markedly unequal in length, hut 5 is considerably shorter. 

 The pollex is abbreviated, but armed with a strong, sharp, curved 

 claw. The plantar pad is irregularly three-lobed and not well 

 defined, but the two carpal pads close behind it are well developed 

 and conical, especially the inner, wliich projects as an excrescence 

 immediately behind the base of the pollex. (Text-fig. 18, D.) 



The hind foot is short and wide, and narrows behind to the 

 heel, which like the rest of the lower surface is nakerl. The four 

 main digits are subequal in length, but thinner than on the fore 

 foot, but otherwise similar, except that the claws are relatively 

 and actually smaller, althougli that of the 4th is elongated and 

 curved. Digits 2, 3, and 4 are set nearly in a straight line and 

 evenly spaced, but digit 5 is set further back and much more 

 widely separated from 4 than the latter is from 3. Digits 2 

 and 3 are thickened above for the accommodation of the two 

 superimposed combs of stiff bristles which overhang the claws. 

 Similar bristles, but thinner and less modified, are found on 

 digits 1 and 4, and in the case of the latter the function of 

 combing the fur is no doubt performed by the long curved claw, 

 the point of which reaches as far as the distal end of the 

 bristle-combs on the 2nd and 3rd digits. The plantar pad is 

 almost suppressd, being mainly represented liy four small henni- 

 spherical tubercles, two in front just behind digits 2, 3, and 4 

 and one at the base of digits 1 and 5 respectively. The area 

 between these tubercles is wrinkled and irregularly papillate ; 

 but the area behind them is smooth and mostly covered by a 

 large callous external metatarsal pad, which terminates anteriorly 

 in a tubercle, and posteriorly falls short of the heel, which, like 

 the inner side of the foot, is covered with thinner skin, the 

 internal metatarsal pad being represented by a tubercle behind 

 the poUical tubercle of the plantar pad. (Text-fig. 18, E, F.) 



The feet of Thrynomys are not like those of any other genera 

 of the group; both fore and hind are perissodactyle. In the 

 fore foot the pollex is minute. The second, third, and fourth 

 digits are short, thick, and armed with long strong claws, the 

 second and fourth being subequal and shorter than the third, 

 which lies between them. They are free from webbing. The 

 fifth digit is much smaller than the fourth, but set close behind 

 it a little in fi-ont of the level of the pollex. The plantar pad is 

 wide, three-lobed, convex in front, and concave behind. The 

 carpal pad, which is separated mesially, at all events, from the 

 plantar pad by a moderately long membranous space, is large 

 and indistinctly divided by a groove and notch in front. (Text- 

 fig. 19,0.) 



The hind foot has lost all trace of the hallux externally. 

 Otherwise the digits are similar to those of the fore foot in 



