60 



CARNIVORA 



ORDER III 



! C 



the strongly convoluted cerebral hemisplieres covering the greater part 

 of the cerebellum and olfactory lobes. It is noteworthy that the Fissipedia 



are differentiated from the Miaci- 

 dae only through the anchylosis 

 of the scaphoid and lunar, the com- 

 plete ossification of the auditory 

 bulla, and the greater development 

 of the brain. 



The large size of the canines, 

 and the presence of shear-like car- 

 nassial teeth, are characters which 

 stand in correlation with a car- 

 nivorous diet. The last premolar 

 in the upper jaw, and the first 

 molar in the lower are usually 

 sectorial, resembling the Miacidae; 

 the teeth in front of these have 

 cutting edges, are tritubercular, 

 and are often small and conical ; 

 those behind have broader crowns 

 and are tuberculo-sectorial. The 

 carnassial teeth are often, but not 

 always, much larger and especially 

 longer than the rest of the molar 

 and premolar series. 



The typical upper carnassial 

 (Fig. 86) is three-rooted, consist- 

 ing of a more or less compressed 

 blade supported by two of the 

 roots, the third bearing an inner 

 tubercle. The blade, when fully 

 developed, is trilobed, but the 

 anterior cusp {a) is always small, 

 and sometimes absent. The middle cusp (a) is conical, high, and pointed, the 

 posterior (c) has a compressed, trenchant edge, and is generally longer and lower 

 than the anterior. The inner tubercle {h) varies in extent, and is generally anterior, 

 though sometimes median, in position. In the Ursidae alone, both the inner 

 tubercleandits supporting root are absent, and there is often a small internal and 

 posterior cusp without a root. In the Felidae, Hijaenidae, and certain Fiverridae 

 there may be two small tubercles instead of one, anterior to the median cusp. 

 The lower carnassial is two-rooted and characterised by a strong develop- 

 ment of the protoconid and paraconid, as against the stunted protocone and 

 rudimentary paracone of the upper molars. The posterior lobe of the 

 blade {/3) is generally larger and higher than the anterior (a), and separated 

 from it by a notch. In the Felidae, only the blade of the lower carnassial is 

 developed, both talonid and inner cusp being absent or rudimentary. In 

 some forms the talonid (y) is greatly developed, broad and tuberculated, in 

 which case the blade is generally placed obliquely. The inner cusp, when 

 present, is generally conically pointed, and placed at the inner side of the blade. 

 All three upper molars may be present, or their number may be reduced 



yPA 



Fio. 86. 



A, Lateral and superior aspect of upper carnassial of dog, and 



B, of lion. C, Lower carnassial of htrpe.'iles, and D, of lion. 



