313—136 INDIAN TERTIARY AND POST-TERTIARY VERTEBRATA. 
compared with the present specimen, it will he found that the two agree in the 
general form of the jaw (especially in respect of depth, and the upward bend of the 
inferior border near the angle) ; in the proportionate length of pm74 and m. 1 ; and 
in the general form of these teeth. The main points of distinction, in addition to 
size, being that the talon of m. i is relatively smaller in the present specimen, and 
the inner cusp considerably larger and placed more exactly opposite the hinder lobe 
of the blade ; while the fore talon of pm. 4 is relatively smaller ; and that tooth 
scarcely diminishes in width anteriorly. 
The fossil resembles some of the primitive cats 1 in having a talon and inner Cusp 
to m. I ; but differs from them in the shape of the hinder part of the jaw; and 
(with the exception of a species described below) in the greater depth of jaw, in the 
subequality in size of pm. 4 and m. 1, and, perhaps, in the larger size of the inner cusp. 
Affinities . — From the foregoing comparisons it appears that the present form is 
most nearly allied to one of the primitive hyaenas ; from which, however, its small size 
and the differences noticed , above probably indicate generic distinction. The 
resemblances between the two are, however, so close that it is probable the fossil 
sh ould be referred to the Eycenidce ; and accordingly the new generic name 
Tjepthycena is proposed for it. The smaller size of the talon of m. 1, and the fore 
talon of pm. 4 in Lepthycena , probably indicates that this genus is not an ancestor of 
Hycena, but that it more probably diverged from some form like Ictitherium ; and 
may possibly be related to the ancestral stock of the primitive cats ; one of which 
will be shown below to present strong resemblances to the present genus. The 
number of lower premolars in the latter is unknown. 
Family V. : FELIDAE. 
Extent . — In classifying the most specialized group of carnivores which may be 
collectively spoken of as “ cats,” Prof. Cope 2 divides them into two distinct families, 
termed the Nimravidce and Felidce : the distinctions between the two being mainly 
founded on modifications of the basi-cranial foramina. Partly owing to the fact that 
these foramina have not been observed in all the species, and partly from the gradual 
transition in other characters from one genus to another, Prof. Mivart 3 prefers to 
class the whole of these animals in the one family Felidce ; and this course will be 
adopted here. There is, however, still some doubt as to the number of genera that 
should be included in the family, since Prof. Cope includes in his Nimravidce the 
genus Procelurus , Filh.; while Prof. Mivart 4 is inclined to refer it to the mustelines. 
Its dentition is, however, decidedly feline ; while the form of its skull, though more 
weasel-like, is not so far removed from that of Archcelurus, as to preclude in the 
present writer’s opinion the possibility of its belonging to the Felidce ; of which in 
any case it must probably be regarded as an ancestral form. Provisionally including 
this genus, the genera of Felidce hitherto described may be tabulated as follows, vis. : — 
1 Vide infra. 3 “ The Cat,” p. 439. 
2 * Amer. Nat.,’ vol. XIV., 1880, p. 833, el. seq. 4 Ibid, p. 435, 
