62 QUADRUPEDS OF MASSACHUSETTS. 



grinders wear away most behind, the front remaining the longest ; 

 but the whole presents a concave, while in the upper jaw, the 

 wearing produces a uniform convex surface. 



Dimensions. 



(Measurements taken from an old female skull.) 



Length of the lower jaw over the palatine bones, 



" from the nasal bones to the crucial ridge, 



" " end of the incisors to the nasal bones. 



Width at the arches, 



Length from the incisors to the meatus, .... 



" of the molars above the sockets, 



" from the incisors to the base of the molars, . 



" " base of the first molar to the foramen magnum 



" of the space occupied by the upper molars, . 

 Width from outside of the posterior grinder to the other. 

 Height of the skull at the insertion of the molars. 

 Breadth of the skull at the base of the processes of the meatus. 



Observations. This remarkable animal is probably driven 

 entirely from the bounds of Massachusetts. It has become, like 

 some other animals, extinct, and is known only in historical 

 records as having formerly been a tenant of our waters. 



There is but little doubt, that all the larger streams, as the Con- 

 necticut, the Hoosic, Housatonic, and Merrimack, as well as some 

 of the lakes, were more or less frequented by this animal. The 

 principal circumstance on which our evidence of the fact rests, 

 is the frequent occurrence of such names as these, the Beaver- 

 Dam, Beaver-Meadow, Beaver-Lake, Beaver-Falls, Slc. 



I shall not enter largely into the history of the Beaver, though 

 volumes have been written on its sagacity and remarkable intelli- 

 gence, from which it would seem that the authors could not say 

 too much in its praise, nor relate stories too wonderful to be 

 believed, or too fictitious to satisfy the curiosity of the credulous. 



That it possesses a degree of sagacity above some animals, is, 

 perhaps, not too wonderful to be believed ; but it is probable that all 

 the curious stories have arisen from the circumstance of its being 

 a quadruped endowed with the instinct of accommodating itself to 

 circumstances, and of providing for itself a curious habitation. 

 What is this more than that possessed by the Squirrel, who builds 



