302 On the Classification of the Cavies. 
them into two genera, one of these being subdivided into 
three subgenera. He recognizes the genus Kerodon, in- 
cluding K. rupestris only, as disunct from Cavia, mainly on 
account of its peculiar sternum and other skeletal charac- 
teristics, while within the large genus Cavia he only gives 
subgeneric importance to the molar characters usually used 
to distinguish Cavia s.s. from the other forms with teeth like 
those of Kerodon, which have generally been included in the 
latter genus. 
Among these, again, he has discovered a character in the 
complete interruption of the maxillary in front of the 
lacrymals, to distinguish Galea (musteloides, boliviensis, spizt, 
&c.) from Cavia s. s. (porcellus, aperea, &c.) and “ Caviella”’ 
(australis, menas, &c.). 
In naming some specimens recently received, I have had 
occasion to examine Mr. Osgood’s classification, which is 
clearly a distinct advance in the matter, though I would 
venture to propose some amplification of it. 
Mr. Osgood’s sections, whether called genera or subgenera, _ 
are all clearly defined natural groups, easily distinguished 
from each other by definite characters, and I would, there- 
fore, suggest that they should all be treated as genera. 
In addition, I would erect a special genus for my Cavia 
niata, which is quite a specialized form, readily distinguish- 
able from the other members of Caviella, in which Mr. Osgood 
includes it. 
The following is a synopsis of the genera, the characters 
not being in any way detailed, as such of them as have not 
been published by Waterhouse and other earlier writers 
have been well described by Osgood :— 
A. Cheek-teeth complicated, as indicated by 
Waterhouse * ipl vide 9 ir, occemep eee 1. Cavia, Linn. 
Genotype, C. porcellus, L. Other species: C. aperea, Erxl., rufescens, 
Lund, cutlerz, Benn., atahualpe, Osg. 
B, Cheek-teeth comparatively simple (¢f. Water- 
house, pl. vi. figs. 1-8). 
a. Toes with claws. ‘ Sternum broad and flat” 
( Osgood). 
a’, Skull shortened, bowed. JIncisors un- 
pigmented. Orbital branch of maxillary 
continuous as a narrow strip in front of 
lacrymals. 
a*. Incisors nearly vertical, their angle to 
the line of the molars, measured as 
described in the footnotet, about 100°. 
* Nat. Hist. Mamm. ii. (1848). 
+ When publishing the method of obtaining this important angle 
(J. Bombay N. H. Soc. xxiv. p. 408, footnote, 1916), I took it from the 
terminal part of the enamel-coy ered front of the tooth, believing that in 
