INSECTIVORA. 



79 



Shrews and Moles, the incisors, canines, and premolars are by no 

 means readily distinguished. Throughout the Order the premolars 

 and molars are covered with minute, pointed cusps, suitable for 

 crushing the insects on which, as may be gathered from their 

 name, nearly all the Insectivora feed. The zygomatic arches are 

 generally either weak or entirely absent. The dentition offers 

 many important differences : thus the Desmans (Myogale) have 

 enormous incisors and small canines, while the opposite is the case 

 in the Moles (Talpd) and the Tanrecs (Centetidce) . And, further, 

 the whole Order is divided into two groups, distinguished by the 

 shape of the molars, which are either triangular and tricuspid, as 

 in the Tanrecs and Golden Moles, or square and multicuspid, as in 

 the Hedgehogs, Moles, and Shrews (see fig. 37, A & B) . 



Skeletons of all the chief types are exhibited ; the most note- 

 worthy are those of the Moles (Talpa) (fig. 38), in which the 



Fig. 38. 



Fore part of Skeleton of Common Mole. A, Side view. B, Front view 



of shoulder -girdle. 



c } carpus ; cl, clavicle ; /, falciform "bone ; h, humerus ; me, metacarpus ; 

 phj phalanges ; r, radius ; sc, scapula ; st, sternum ; u } ulna. 



