THE CAT. 



[CHAP. xv. 



and which, though it has two upper tubercular molars, has the 

 hinder one quite rudimentary.* 



The civets, again, differ from the hyaenas, in having a lower 

 tubercular molar. Bat the same accomplished palaeontologist has 

 discovered another fossil form, Hycenictis,^ which is hyaena-like, but 

 yet has a rudimentary lower tubercular molar tooth. 



But can we get any probable suggestion as to the origin of the 

 cat's sub- order, the I^Eluroidea ? To be able at all to answer this 

 question, we must glance at fossil forms related to the other car- 

 nivorous sub-orders. As regards the dogs (Cyncdded), the existing 

 Otocyon, and the fossil genus Gakcy 'mis, } :lead down to forms of more 

 general affinities which may have been dog ancestors. One such 

 is Cynodictis (of the upper eocene), and which leads on to Cynodon,\\ 

 which is a still more generalized form, showing, in M. Graudry's 

 opinion, certain affinities to the civets. 



Amongst iheArctoidea,t}iQ weasel faxmlyfMustelida) is inasmuch 

 as it is an arctoid family distinguished by a variety of characters If 

 from the Viverridce. Amongst the characters by which it differs is 

 that of the absence of a second upper tubercular molar. TnLutrictiSy** 

 however, we have a musteline form in which the second upper 

 tubercular molar is present, though very small, ff In Procelurusfif 

 also, we have a fossil with seeming musteline and viverrine affinities, 

 yet with teeth which approximate to those of the cats. The true 

 bears (Ursidce) were preceded by mammals such as the miocene 

 Hycenarctos, which, with the help of Amphicyon,\\\\ apparently 

 connects them with the dogs. 



The three sub- orders of carnivora being thus brought near to- 

 gether in the past, to what other group can they i.e., can the 

 whole order Carnivora be affiliated ? What may probably have 

 been the cat's ancestors in a yet more remote degree than the un- 

 known common stock whence the three existing suborders gradually 

 diverged ? 



5. We have seen Iffl that the oldest tertiary mammal Arctocyon, 

 has characters which give it some claim to be nearly allied to the 

 progenitor of all true carnivora. But besides such characters, we 

 find in it conspicuous defects of palatal ossification, and a low form 

 of brain, which characters would seem to make it impossible that its 

 claim to be an ancestor of the carnivora should be established. 

 Moreover, we have seen that there are a number of eocene fossils 

 such as Pterodon, Proviverra, Hycenodon, Palceonyctis, &c.,*** which 

 agree in having (amongst other common characters) teeth which are 

 not differentiated into premolars and an upper and lower sectorial 



* See Les Enchainements, p. 217, 

 fig. 286. 



t L. c., p. 218, fig. 289. 



J See ante, p. 507. 



See ante, p. 50. 



|| See Les Enchainements, p. 215, 

 figs. 282 and 283. 



U Ante, p. 475. 



** See ante, p. 507. 



tf See Les Enchainements, p. 219, 

 fig. 290. 



JJ See ante, p. 435. 



See ante, p. 507, and Les Enchaine- 

 ments, pp. 212 and 213, figs. 278 and 279. 



|| || See ante, p. 507, and Les Enchaiiie- 

 uients, p. 212, fig. 277. 



Iff See ante, p. 506. 



*** See ante, p. 505, 



