﻿CANIS. 15 



D.m. 1 is a good deal like pm. 2, the blade having a principal cone and often 

 a slight posteriorly-placed accessory cusp. The two teeth differ, however, in the 

 fact that d.m. 1 has the roots strongly divergent. 



D.m. 2, the milk carnassial, is the largest of the deciduous teeth. The major 

 portion of the crown is formed by a powerful bilobed blade, of which the anterior 

 lobe is conical, the posterior more depressed and chisel-like. In front of the blade 

 are two low cusps. There is further a prominent inner cusp anteriorly placed. 

 This is supported by a special root, and two other strong roots support the outer 

 part of the tooth. 



D.m. 3 is a very irregular tooth. The outer edge, which bears certain ill-defined 

 cusps, is raised anteriorly and supported by a small root, while posteriorly it is 

 depressed and supported by a strong triangular, divergent root. There is an inner 

 cusp supported by a third root. 



(b) Milk Dentition of the Lower Jaw. — D.i. 1, 2 and 3. These are even slighter 

 and simpler teeth than those of the upper jaw, and have very long, tapering- 

 roots. 



D.c. This is practically identical in character with that of the upper jaw. 



D.m. 1. — Except for its smaller size and the more divergent character of the 

 roots, this is identical with pm. 2. 



pm. 



D.m. 2 very closely resembles pm. 3, but the accessory cusp anterior to the 

 principal cone is better developed than in that tooth. 



D.m. 3, the milk carnassial, is a large tooth supported by two strong divergent 

 roots. Four fifths of the crown is formed by a bilobed trenchant blade, and 

 behind this is a considerable cusp. 



c. The Vertebral Column (Plate VI). 



Little or nothing can be mentioned as specially characteristic of the vertebral 

 column in the Canidas in comparison with that in other Carnivora, but the variable 

 number of the caudal vertebras may be alluded to, the number ranging from 

 seventeen to twenty-two. There are thirteen thoracic and seven lumbar vertebras. 

 Only three vertebras are fused together in the sacral region, while in bears the 

 number may be as many as five. 



d. The Limb Girdles. 



The Shoulder Girdle. — The scapula (Text-fig. 1) scarcely calls for special 

 comment, though it may be mentioned that the coracoid process is very slightly 

 developed. The British fossil specimens are almost always in a very fragmentary 

 condition. The clavicle is in a much reduced state, though better developed than 

 in bears. 



