FELTS SPEL^A. 75 



as far as possible, in fig. 2, the appearance of the milk molar dentition in one maxillary. 

 The tooth is supported by one small cylindrical and slightly tapering fang. 



Milk molar, 3. (Figs. 1, 1', 1", 2, 2', 6.) — This tooth, which is sectorial, is by far the 

 largest of the series. The cone {a) of this tooth is central, compressed, rounded externally, 

 and flattened internally; but a distinct buttress can be traced from the summit to the internal 

 base, where a few minute prominences represent the tubercular cusp (/). It is furnished 

 with sharp-cutting edges, anteriorly and posteriorly, the latter being nearly perpendicular, 

 and separated from the long, horizontal, blade-like cusp (c), by a deep cleft ; the latter, in 

 the unworn tooth, has the appearance of being double, the trenchant edge being deeply 

 waved, but the cleft, if any, is very slight; the tooth ends posteriorly in a much com- 

 pressed but rounded lobe, formed by the cingulum ; anteriorly the knife-like edge of («) 

 is inclined at an angle of about 45° to the horizontal line, and is divided from the cusp 

 {b) by a cleft. The cusp ((5) is of blade-like form, but short, and with a central point, 

 from which descends obliquely in a backward direction a sharp-edged buttress to the 

 tubercular (/), anteriorly this is again separated by another cleft from the " accessory " 

 cusp {d), which is again of a short blade-like form, but rounded anteriorly. The summits 

 of ((5, c, d) are nearly in the same horizontal line, from which the cone (a) rises to a con- 

 siderable height. They are so disposed that the trenchant edge they form is concave 

 externally. The cingulum is strongly developed, and has two rows of minute raised dots 

 on it extei'nally, and one similar row internally. It is supported by two similar highly 

 compressed trapezoidal divaricate fangs of flat oval section, the anterior supporting half 

 («), {J)), and {d), and the posterior the rest of {a) and the whole of (c) ; a normal cyhn- 

 drical internal fang supports the very minute representation of (/). 



Milk molar, 4. (Eigs. 1, 1', 1".) — The minute cusps and ridges which point out the 

 true homologies of this tooth in Felis being easily worn, their determination is very 

 difficult, except in the very young specimens. The crown is somewhat triangular in form, 

 the longest side of the triangle forming the anterior border. The posterior angle forms a 

 rounded lobe, on the summit of which is a minute cone, traversed by a sharp cutting ridge ; 

 this descends posteriorly to a minute cusp at the extremity of the angle, and anteriorly it 

 turns outward, and terminates in the very young lion at a minute cleft, which separates it 

 from a ridge forming the summit of another cusp, of the same shape as (^) in PM4 

 on the external angle of the tooth. The minute cone is the homologue of («), and the 

 small posterior cusp of (c). From the summit of {a) descends inwardly a broad rounded 

 buttress, from the base of which arises, in very young lions, a small conical cusp, Avith 

 distinct furrows passing from the summit to the base. This is the homologue of the tubercle 

 (/). This portion is broken in our specimen oi Felis spelaa, and the crest connecting («) 

 and {b) is continuous, instead of being interrupted by a cleft. This appears to be the result 

 of wear. In other respects the teeth of the two animals resemble each other. The body 

 of the tooth is supported by a broad flat fang, passing backwards into a shallow alveolus. 

 This fang appears from its formation to be essentially double, and to represent the fangs 



