82 Head of fossil Ovis.—F* ossil Chiton. 
a marine animal of the Walrus or seal race, and a borderer of the 
ancient ocean. Since my return from Zanesville, I have received 
the larger portion of a similar tooth, imbedded in dark colored car- 
bonate of lime. Jt was found on Wills Creek, near the lias deposits, 
about forty miles east, and had fallen out from a calcareous rock which 
lies near the tops of the hills, one hundred and fifty feet above the 
bed of the creek.* 
Head of fossil Ovis.—Description.—The whole head is much 
rounder and fuller than the domestic sheep. Breadth of os frontis 
between the eyes, three and a half inches: orbitary processes very 
prominent and one and six eighths of an inch in diameter: space be- 
tween the horns, two inches at the base, which incline backward at 
an angle of about sixty degrees. Base of the head, measuring from 
occipital hole, to nasal extremity, eight inches, a part of which is 
broken off. Six stout molar teeth on each side; a mamillary pro- 
cess on each side of the upper maxillary bones, one third of an inch 
high, with broad base, opposite the second molar tooth, counting 
from back forward. They are probably the supports of a fleshy 
substance for the growth of tufts of long hairs. Palate bones slight- 
ly arched. The medullary portion of the horns now remaining, 
is two inches long; thin on the upper side, and one inch thick on 
the under, and one and a half inches deep. From their direction, 
they were probably more like goats’ horns than those of a common 
sheep. ‘The animal differed from the domestic sheep in the follow- 
ing particulars. In the domestic animal, the space between the 
horns is much less ; between the eyes, the distance is also less. The 
eyes themselves are considerably smaller, and there is no mamillary 
process on the maxillary bone, which is the strongest mark of a spe- 
cific difference between the modern and the ancient races. It may 
be named Ovis mamillaris. Fig. 19, gives a view of the head. 
Fossil Chiton.—Description.—Length, eight inches; breadth, 
six inches; nearly cordiform in its outlines, and fully one inch in 
thickness on the lateral margins. Back slightly convex. Shell, 
with ten valves; longitudinally arranged and’ finely united on the 
back of the animal, somewhat resembling spinal articulations. Sur- 
face of each valve, smooth, or very slightly striated, and distinctly 
* In excavating the new canal this summer, in the deep cutting between the 
heads of Sandy and Beaver Creeks, many fossil bones were found. Among them, 
I am informed by J. Pierce, Esq., are some similar to these, but more than three 
times as large. 
