COMPAKATIVE ANATOMY OF THE TEETH. 2*79 



in number, shape, and size. The most common character- 

 istic found to prevail is the presence of "several sharp 

 points upon the crowns of the true molar teeth." 



This order is divided into the families of moles (talpidee), 

 shrews (solicidge), and hedge-hogs (erinacidas.) 



The mole of the cape, as it is called, according to Mr. 

 Owen, has forty teeth. Its dental formula is to the up- 

 per jaw on either side, three incisors, one bicuspid, and six 

 molars ; to the lower jaw, three incisors, two bicuspids, and 

 five molars. The American mole has thirty-six teeth: to 

 the upper jaw, on either side, three incisors, one canine, 

 three bicuspids, three molars; to the lower jaw_, two inci- 

 sors, no canine, three bicuspids, three molars. The common 

 mole has forty-four teeth, in the arrangement of which 

 there is some difference among naturalists. M. Cuvier 

 rates no canine to the lower jaw, and gives four bicuspids 

 and three molars on either side to both jaws. Mr. Bell 

 allows two canine to the lower jaw, gives no bicuspids, and 

 makes seven molars to the upper, and six to the lower jaw, 

 on either side; while M. Blainville has, to both upper and 

 lower jaw, on each side, four incisors, one canine, three 

 bicuspids, three molars. 



In the hedge-hog, one variety has thirty-six teeth. The 

 formula given is, incisors two, canine one, bicuspids three, 

 molars three, to both upper and lower jaw, on either side. 

 The common hedge-hog has the same number, but differ- 

 ently arranged as follows: incisors three, bicuspids four, 

 molars three, on either side, in each jaw. Another variety 

 has forty-eight, i. e. incisors three, canine one, bicuspids 

 four, molars four, on either side, in each jaw. 



CHEIROPTERA. This order includes two divisions of the 

 bats first, those that live on insects, and second, those 

 that live on fruits. 



The number of teeth belonging to the first is thirty- 

 eight, i. e. incisors two, canine one, bicuspids three, molars 

 three, to the upper jaw, on either side ; and to the lower, 

 incisors three, canine one, bicuspids three, molars three. 



The vampire or blood-sucking bat has but twenty teeth. 



