230 
PALAEONTOLOGY OF NEW YORK. 
forms, and all those from the base of the Upper Helderberg to the Chemung, 
inclusive, are cancellated, or marked only by longitudinal strife. The Bohemian 
species, which approach those of America in general form, surface-markings, 
and position of siphuncle, are generally of the curved forms. Of these, several 
are apparently allied with species described in the present volume, and will be 
noticed in the comparison of species. 
The number of species of Ortlioceratites, including those of the genus or 
subgenus Endoceras, heretofore described and recorded from the American for¬ 
mations, so far as known to me at the present time, is three hundred and eight, 
to which will be added in the present volume forty-six species. The species 
described in the present and preceding publications are distributed in the geo¬ 
logical formations according to the following table. 
Of the subgenus Endoceras, twenty-seven species and varieties have been 
described and recorded; but all the forms of this type, with a single excep¬ 
tion, are restricted to the Quebec group, the Black River and Trenton lime¬ 
stones,* and are included in the second column of the table. 
FORMATION. 
Orthoce ras. 
No. ofspeoies. 
Endooeeas. 
No. of species. 
Potsdam sandstone ........ 
Caleiferous sandstone . . . . . . . 
is 
Quebec group . ........ 
21 
3 
Chazy limestone ........ 
17 
Black River limestone . . . . . . ... 
20 
5 
Trenton limestone ........ 
41 
17 
Utica slate ......... 
2 
1 
Hudson River group ....... 
32 
1 
“Anticosti group” ........ 
3 
Medina sandstone ........ 
3 
Clinton group ......... 
12 
Niagara group ........ 
40 
Lower Helderberg group ....... 
9 
Oriskany sandstone ........ 
1 
Upper Helderberg group . 
30 
Hamilton group ........ 
29 
Portage group ......... 
4 
Chemung group ........ 
19 
Waverly group ......... 
7 
Lower carboniferous ....... 
8 
Coal measures ......... 
8 
Permian ......... 
2 
Total ......... 
323f 
27 
* Endoceras longissimum, and E. multitubulatum are recorded as occurring in the Black River and 
Trenton limestones, and E. proteifonne in the Trenton limestone, Utica slate, and Hudson River groups. 
f The discrepancy between the number of species, as stated in the text above, and the summary given in this 
table, is owing to the omission of three synonymic names, and the transfer of 0. acicula to the genus Coleolus. 
