PROFESSOR PETERS ON THE GENUS PECTINATOR. 399 
which becomes more rigid and forms a fringe at the margin of the ear; internally, only 
towards the hinder part, sparingly provided with short hair. ‘The whole ear-conch 
cannot be said to be more developed than in Ctenodactylus; but the antitragus, 
entirely wanting in Ctenodactylus, is, although very small, distinguishable; and the 
anthelix, which forms in Ctenodactylus a simple arched prominence, with hairy margin, 
is much lower, naked, and more of the human form, anteriorly bifurcate. In this 
latter respect (the development of the anthelix) the Ctenodactyli differ entirely from 
Dipus (egyptius), Chinchilla, and Habrocoma, and show a greater affinity to the 
Echinomyes. The eyes are of moderate size, three times as distant from the end 
of the snout as from the ears, and separated from each other by a large interspace. 
The snout is protruding, and the cleft of the mouth small, as in most of the Rodents, 
particularly in the Rats, Echinomyes, and Chinchille. The upper lip is not cleft, nor 
hairy behind the incisors, as in Dipus, but merely notched, as in Hehinomys and 
Chinchilla, and has a mesial naked’ narrow groove descending from the small 
triangular rhinarium between the falciform nostrils. Above the nostrils is to be seen 
the same transverse fold of skin which has been observed in the Chinchille. ‘The 
moustaches are formed by seven longitudinal rows of long bristles, partly much longer 
than the head, the longest measuring 8 centimetres. 
The fur of the body is of moderate length, about 14 centimetre long, and, although 
yery soit, less so than in the Chinchille. 
Pectinator has, like Ctenodactylus, only two lateral teats, one on each side, 1 centi- 
metre behind the elbow when the humerus is laid backwards. In this respect the 
Ctenodactyli ave also more allied to the Chinchille and the Echinomyes than to the 
Dipoda, which have a pair of teats between the fore legs, and one on the inner side of 
the hind legs. The external sexual parts at first sight do not differ very much in the 
different sexes, the clitoris of the female being perforate, and hardly less protruding 
than the penis of the male. The vagina is separated from the anal aperture only by 
a narrow isthmus; and the testes form prominences externally, at the sides of the base 
of the penis. 
The extremities are in form and proportion exactly like those of Ctenodactylus. 
Both the anterior and posterior limbs have externally only four toes, the single-jointed 
thumb being perfectly concealed by the skin. The upperside of the hands and feet is 
closely covered with short adpressed hair, which becomes longer and setaceous towards 
the end of the fingers and toes, thus overreaching the strongly curved pointed claws. 
As in Ctenodactylus, two rows of bristles on the two inner toes of the hind feet are 
particularly strong and comb-like. The palms and soles are naked, and of a black 
colour. There are three large patches behind the base of the fingers and toes, two 
roundish ones beneath the carpus, and two longish ones beneath the metatarsus. The 
patches under the ends of the toes are transversely furrowed. The last finger and toe 
' In the Ohinchille also this groove is naked, and only appears hairy in dried specimens. 
Sat 
