﻿FELIS SPEL^EA. 71 



the lower jaw in Felis spelaa precisely resembles that of the lion, except in the size of 

 the larger specimens. There appears to be a very slight difference in the form of PM3 in 

 most specimens of tiger. 



Incisors. (PL XII, fig. 1, 2). — FT and 2 agree in all respects save that of size, the latter 

 being the larger in every dimension, though not to the extent indicated in our plate; 1 1, being 

 the tooth of a much smaller animal than that to which 1 2 and 3 belonged. The crown 

 (a) is conical in the unworn tooth, and slightly recurved ; it is hollowed behind, and 

 the base of the hollow is filled by a small lobe to which a slight ridge descends from the 

 apex ; and, on the outer {posterior) side is a small cleft which marks off a cusp (c) from 

 the trenchant edge of the tooth. The fang is long and slightly recurved, subcylin- 

 drical, but compressed. 13 (fig. 3) is characterised by the larger size, the higher crown 

 the greater distinctness of the lateral cusp, and the greater curvature of the fang. 

 The incisors both of the upper and lower jaw can be distinguished from those of the 

 hysena, by the shorter crown, the smoothness of the enamel, and by the greater length of 

 the fang. The incisors of the wolf have still longer crowns, and shorter and more 

 slender fangs. The incisors of the bear are less curved, and more conical in the crown ; 

 and both fang and crown are stouter. We know of no other fossil teeth that can be 

 confounded with the incisors of Felis spelaa. 



Canines. (PL I, VI, XII, figs. 4, 5, 6). — The lower canines are differentiated from the 

 upper by the more decidedly sigmoid curvature of their anterior aspect, their somewhat 

 smaller size, and the presence of but one groove or " sillon" on the exterior of the crown. 

 The crown is shorter, stouter, and more curved, and the internal triangular area marked 

 off by the sectorial ridges is more distinctly marked, and smaller, owing to the more back- 

 ward position of the anterior ridge, which ends near the cingulum in a small but well- 

 marked tubercle. Both ridges in the unworn tooth are strongly serrated. The cingulum 

 is but feebly developed. The fang is hardly so massive as that in the upper jaw ; it is 

 somewhat compressed, and truncated at the base. The anterior outline of the whole tooth 

 is a gentle convex curve, the posterior or internal is more or less slightly sigmoid. The 

 postero-external face and point are often worn by the upper canine, sometimes to such an 

 extent as almost to obliterate the external sillon. Similar remarks apply to the size 

 of these canines (including those with regard to the small specimens from Ravens Cliff), 

 as we made with reference to those of the upper jaw. 



Premolars. — PM 3 (Pis. I, VI, XII, figs. 7, 8, 9) of the lower jaw consists of a 

 primary trenchant cone (a), accompanied by the anterior and posterior cusps (<5) and (c). 

 The cingulum is strongly developed posteriorly, forming a sharp edge interiorly. The 

 crown is somewhat oval in section, and is supported by two fangs, connate, and nearly 

 parallel in the larger, and highly divaricate in the smaller specimens, the posterior 

 being the larger of the two. The anterior cusp (b) is obsolete in some specimens 

 of both larger and smaller teeth. The anterior portion of the crown is always much 

 smaller in transverse measurement than the posterior. In this last respect it resembles 



