424 MONOGRAPHS OF NORTH AMERICAN RODENTIA. 
A cast of a skull (from an unknown locality) now before me has a length 
of over twelve inches, considerably exceeding in size the Clyde skull 
described and figured by Dr. Wyman. The species being known only 
from a few cranial and dental remains, it is impossible to say much respect- 
ing its general form or probable habits. It may have been aquatic, like 
the Beaver; but of this there is no evidence. The form of the occipital 
condyles and the surfaces for the attachment of the cranial muscles show that 
it probably differed greatly in habits from the Beaver. Mr. J. W. Foster 
described (anonymously) a radius found with the two mandibular rami 
discovered at Nashport, Ohio, which he presumed to belong to the same 
animal. This bone he describes as being ten inches in length, and as 
measuring two inches across the head and one and a half across the distal 
extremity.* In a later notice of the same specimens, Mr. Foster makes no 
mention of this bone, and no other naturalist appears to have given any 
further account of it. Mr. Foster regarded it as “an animal closely allied to 
the Beaver, but far surpassing him in magnitude”. Dr. Wyman not only does 
not refer to it as a Beaver, but dwells especially upon the important differ- 
ences that separate it from that animal. 
The remains of Castoroides ohioensis thus far reported consist of the two 
right rami of the lower jaw and an upper incisor from Nashport, Licking 
County, Ohio (from which the animal was originally made known), first 
described by Foster; the skull and a right ramus of the lower jaw from 
Clyde, Wayne County, New York, described (and the skull figured) by 
Wyman; the ramus of a lower jaw from. Memphis, Tennessee, also described 
and figured by Wyman; “two molars, an upper incisor, and two petrous 
bones ”, from near Shawneetown, Illinois, and fragments of teeth from the 
Ashley River, South Carolina, described by Leidy. A skull from near 
Charleston, Coles County, Illinois, is also mentioned by Leidy. Hall and 
Wyman both refer to the discovery of its remains near Natchez, Mississippi, 
and in Louisiana; but I have met with no description of specimens from these 
localities. Winchell mentions the discovery of its remains in Michigan, of 
which nodescription has yet appeared. In the Museum of Comparative Zodlogy, 
Cambridge, Massachusetts, are portions of several lower incisors and parts of 
several.molar teeth, from Dallas, Dallas County, Texas, collected by Mr. J. Boll, 
from “alluvial” deposits on the Trinity River, associated with remains of an . 
* Amer. Journ. Sci, and Arts, Ist ser., vol. xxxi, 1837, p. 80. 
