OCTODONTID.E 483 
and two external enamel-folds; the ears are comparatively small ; 
the tail usually of considerable length, and the general form some- 
what Rat-like. The typical C. pilorides is somewhat smaller than 
the Coypu, and is confined to Cuba; it is remarkable for the 
sub-division of the lobes of the liver into a number of lobules. 
C. brachyurus and C. prehensilis are also confined to Cuba. In 
Jamaica the genus is represented by C. melanurus, which is somewhat 
smaller than a Rabbit, and has no secondary lobulation of the liver.! 
Aulacodus.°-—Upper incisors with three deep grooves; molars 
as in Capromys. Fur very harsh; tail moderate, sparsely haired ; 
manus with rudimentary pollex, and small fifth digit; pes with no 
hallux, and rudimental fifth digit. One species (4. swinderianus), 
from Western and Southern Africa, which attains a length of nearly 
2 feet, and dwells in burrows. 
Plagiodon.2—Allied to Capromys, but with the enamel-folds of 
the molars very complex, and forming a kind of zig-zag pattern in 
those of the upper jaw. Represented only by P. edium of Hayti 
and Jamaica. 
Loncheres* and Echinomys.6—These genera include small South 
American species, in most of which flattened lanceolate spikes are 
mingled with the fur. The majority of the species occur in Guiana 
and Brazil, but one species of Hchinomys has been recorded from 
Central America. Fossil remains of both genera occur in the 
cavern-deposits of Brazil. 
Mesomys..—This genus resembles Loncheres externally, but the 
pollex has a short curved claw, and there are no spines in the fur. 
Dactylomys..—A Brazilian genus presenting the following dis- 
tinctive features. Ears short; tail long and scaly ; pollex minute ; 
third and fourth digits of manus elongated, with short convex nails. 
Incisors flat; molars divided into two lobes, each of which has 
a single enamel-fold. Represented by two species, D. typus and 
D. amblyonyx, both of which seem to be rare and but little known. 
In the elongation of some of the digits Dactylomys recalls Chiromys 
among the Primates. 
Cercomys..—This South American genus is usually placed near 
Carterodon, from which it is readily distinguished by the pointed 
muzzle and the plain incisors. 
1 For description and anatomy of this species see Dobson, Proc. Zool. Sov. 
1884, p. 233. 
2 Temminck, Monographies des Mammiferes, vol. i. p. 245 (1827). 
3 Cuvier, Ann. Se’. Nat, sér, 2, vol. vi. p. 847 (1836). Amended. 
4 Tlliger, Prodromus Syst. Mamm. p. 90 (1811). 
5 Desmarest, Nouv. Dict. d’ Hist. Nat. vol. x. p. 45 (1817). Amended from 
Echimys. 8 Wagner, Wiegmann’s Archiv, 1845, pt. 2, p. 145. 
7 Geoffroy, dun. Sei. Nat. sér. 2, vol. x. p. 126 (1838). 
8 F. Cuvier, Iammiferes, 6ine livr. (1829). 
