OF DENISON UNIVERSITY. 
77 
count will be given of the Brachiopoda and Lamellibranchiata of the 
group, as far as studied. To this are appended partial accounts of 
the Gasteropoda and Trilohita of the same. The next paper will con- 
tain a continuation of the account of the latter groups, with a study of 
the bryozoans and corals of the group. The latter present a few 
features of special importance in the identification of the stratigraphi- 
cal relations of this group. 
Great pains have been taken in the identification of specific forms, 
and new species have been formed only with reluctance, and when there 
seemed to be an absolute necessity for such a course. Nevertheless 
quite a large number managed to creep in. Of these the most inter- 
esting are the series of forms which have so far seemed characteristic 
of that portion of the Clinton Group, here called the Beavertown marl. 
They are to be specially noticed for their small size, being accompan- 
ied with only a few larger species. 
If the writer has anywhere been deceived in his judgment, he 
would be glad to receive such information as would be useful in cor- 
recting the same, since upon the correctness of the identification of 
the fossil forms must depend the correctness of all discussions as to 
the stratigraphical relations of the Clinton Group of Ohio. 
In the description of . fossil forms the nomenclature used by Hall 
and Meek has been adopted, and where species are identified with, or 
described as closely related to forms already published by these or 
other authors, the description of Ohio forms has been as far as possi- 
ble adapted to the original description. However, no statement has 
been repeated which is not fully vouched for by specimens on hand, 
and conformity means only an acknowledgement of the excellence of 
the descriptions taken as a model. 
Most of the species described in this paper may be found in the 
writer’s private collection. Valuable assistance, however, has been 
afforded by numerous friends, both in the loan of specimens and books, 
as well as in such general information as has proved valuable from time 
to time. Among others, the writer feels specially indebted to Mr. E. 
M. Thresher and Mr. Geo. Caswell, of Dayton — both active collect- 
ors of the Clinton fossils near that city. He also wishes to express 
his appreciation of the kindness and interest shown him by Prof. Ed- 
ward Orton, of the Ohio Geological Survey, a man of eminent ability, 
and whose careful, painstaking work has justly won him a place among 
the most honored of i\.merican geologists. 
