74 Th< American Geologist. August, 1893 
upper incisor from Nashport, Licking county, Ohio, (from 
which the animal was originally made known) first described 
by Foster; the skull and the 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 Mem- 
phis. 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, Miss., and in Louisiana. Winchell men- 
tions the discovery of remains in Michigan of which no 
description has yet appeared. In the Museum of Comparative 
Zoology, Cambridge, Mass., are portions of several lower in- 
cisors and parts of several molar teeth, from Dallas, Dallas 
county, Texas, collected by Mr. J. Ball, from 'alluvial' deposits 
on the Trinity river, associated with the remains of an extinct 
horse and the Mastodon. There is also in the Museum of Com- 
parative Zoology an excellent cast of a very large skull from an 
unknown locality ,but probably from either Illinois or Michigan."' 
(May not this be the skull now in the National Museum at 
Washington, from Lenawee county, Michigan?) 
In the eighth report of the Minnesota Survey is an account 
of a large specimen of a lower jaw found at Minneapolis. The 
same is figured and described by N. H. Winchell, with some 
comparisons with former discoveries. 
As to geographical range, the remains of Castoroides are 
found from South Carolina and Texas to Minnesota. Michi- 
gan and New York. 
As to time, these largest of rodents living or fossil, were 
among the latest extinct mammals of the Quaternary. 
A CRITICAL NOTICE OF THE STRATIGRAPHY 
OF THE MISSOURI PAL/EOZOIC. 
By <;. ('. Broadhead, State University, Columbia, Mo. 
The Arcluean includes the granites and porphyries of south- 
eastern Missouri. They are intersected by dykes of diabase 
and dolerite, but in no instance have trap dykes been observed 
penetrating more recent formations. 
