58o CHORD AT A. 



olfactory organ. In these respects the Mystacoceti are not 

 so completely adapted to aquatic habit as the Odontoceti. 



Order XII. — Carnivora. 



The dog and cat have been taken as types of the order 

 Carnivora. They really represent the highest of the Carni- 

 vora^ and the characters of the order are somewhat wider 

 than those deduced from these two types. As in the case 

 of the Ungulata^ they present a series in which certain 

 structural characters graduate from one end to the other. 

 They have chiefly to be distinguished from the Insectivora 

 and, in a more remote degree, from the Ungulata, 



The great majority are carnivorous or flesh-eaters and 

 are terrestrial cursorial types. They have usually at least 

 four toes, which are armed with claws or unguiculae, never 

 hoofs or unguae, as the limbs are nearly always called upon 

 to perform other duties than locomotion. 



The diet reflects itself in the dentition. They are always 

 diphyodont and may have a large number of teeth. The 

 teeth never have persistent pulps, the canines are alw^ays 

 prominent, long and pointed; the incisors are usually §, 

 small and pointed, and the molars are usually cusped with 

 cutting edges, often tritubercular. The enamel is usually 

 little worn and there is no cement. 



There is always a more or less prominent postglenoid 

 process of the squamosal, preventing backward motion of 

 the mandible, and the condyle is transversely elongated ; 

 these modifications being connected with the " grip " as 

 described in the " Cat" and " Dog." 



The stomach is simple and the intestine comparatively 

 short, with a short or simple caecum. The uterus is bi- 

 cornuate and the placenta zonary and deciduate. 



Other skeletal characters to be noticed are the almost 

 entire absence of the clavicle, the complete condition of 

 radius, ulna, tibia and fibula, the fusion of the scaphoid and 

 lunare bones into a scapholunar and the common occur- 

 rence of an entepicondylar foramen (in the humerus). 



All the Carnivora show a well-convoluted cerebrum 

 which partially covers the cerebellum. 



As in the case of several orders, the Carnivora are 

 sharply divided into two sub-orders, differing mainly in their 



