34 Bulletin of Laboratories of Denison University [Voi xi. 
Cephalopoda. Gomphoceras. sp., Orthoceras ohioense. 
Crustacea. Dalmanites calypso. H., Phacops rana. Green., 
Proetuscrassimarginatis. H., Proetusplanimarginatus. M., Proe- 
tus rowi. (?). 
The features of the fauna are the following : 
1. Abundance of Tentacidites. These sometimes almost 
cover the surface of a stratum, and closely resemble the corres- 
ponding layer at Marion. They lie near the summit of the 
quarry. 
2. Abundance of Productella spimdicosta. This is the 
only locality in Ohio known to the writer where this form is 
common. 
3. Abundance of cephalopods of the Gomphoceras type. 
None are well preserved. 
4. Abundance of specimens belonging to the genera Par- 
acyclas, Conocardium, Favosites, and Stropheodonta. 
5. Abundance of Pholido strop Ida nacrea. This is absent 
or only doubtfully present in all sections previously reported 
on. It is often larger than the forms figured in the New York 
reports. One specimen was found which measured more than 
I 1-8 inches along the posterior part, but of this more than 1-8 
of an inch was occupied by the cardinal projections. Some 
times the cardinal extremities are mucronate, sometimes they 
are rounded. In the last case the hinge line does not represent 
the maximum width of the shell. Concentric lines of growth 
are conspicuous, but radiating striae are obscure or absent. The 
surface shows a nacreous luster, but the metallic hue sometimes 
seen on the New York form is not present here. The convex- 
ity of the ventral valve is usually considerably less than that 
figured in the New York reports. It is less than some Cana- 
dian forms also, with which a comparison has been made. 
None of the individuals show crenulations on the cardinal 
area, but the latter is rarely seen on specimens from any lo- 
cality. The ventral valve only is found. A comparison of the 
muscular scars on the ventral valve with those figured in the 
New York reports shows a very close resemblance and leaves 
no doubt as to the correct identification of the specimens. 
