125 



tell us. Mr. Kenni.cott says they are sometimes baked whole, or are bet- 

 ter, parboiled in milk, and afterwards " fatted down." 



Kegardihg the occurrence of this animal in Southern Ohio, I have the 

 following note from Mr. Langdon : 



"Not very common, but can not be called rare. Burrows usually fonnd in the banks 

 of small creeks. On June 11th, 1876, I noticed a Woodchuck climbing down a tree in a 

 piece of woods, near Madisonville. He was about thirty feet from the ground when I 

 first saw him, and was coming down head first, although the tree was vertical or nearly 

 so, and about fifteen inches in diameter. As I was not aware that this species was in the 

 habit of climbing trees, I made a note of the circumstance at the time. The identifica- 

 tion of the species was complete, as I approached within twenty feet of the animal be- 

 fore it reached the ground, and found its barrow within a few yards of the tree. It suc- 

 ceeded in getting there, however, before I did, on account of the dense undergrowth." 



The above observation of this species climbing trees is interesting. Mr. 

 Kennicott states that it sometimes crawls up a leaning tree, or into thick 

 clusters of bushes overgrown with vines, on which it is fond of lying in 

 warm summer days. 



FAMILY CASTORID^. 



This family has been associated with the Sciuridse, as also has Haplo- 

 donlidas. The three families are so nearly allied as to be placed by Al- 

 ston in the same series — Sciuromorpha. 



The Beavers dififer from the Squirrels in being adapted to an aquatic 

 mode of life ; they also lack the strongly developed post-orbital processes 

 of Sciuridse. Instead of truly rooted molars, with multiple fangs, short 

 crowns, and tuberculated triturating surface, undergoing much change 

 by attrition, as in Sciuridss, the molars have, in Oastoridse, a long, persist- 

 ent, dentinal pulp; the teeth continue to grow for a long period, becom- 

 ing truly K)oted only late in life. The teeth, moreover, are single-rooted ; 

 have no well d ifined coronal portion, and change little by attrition. The 

 lower jaw is massive, and its symphisial surface long. The long incisors and 

 general structure of the skull indicate great incisive power — the Beavers 

 being gnawers "par excellence." 



The living representatives of the family belong to the genus Castor. 

 Other genera are represented by fossil forms. 



Castormdes ohioensis, Foster, the "Fossil Beaver" of North America, as 

 large as the full-grown Black Bear, exeeding even the Capabara, the 

 largest of existing Rodents, has been referred to this family, but is now 

 the type of the family Castoroididas, Allen. This interesting animal was 

 first described by Mr. J. W. Foster, from two mandibular rami and a radius 

 ten inches long, two inches across the head, and an inch and a half across 

 the distal extremity. 



