ENDOCEEATID-i:. 
155 
XatioDal Collection. It measures 6 inches in length, 5 inches in 
its greatest and 4 in its smallest diameter. The specimen is broken 
along the longitudinal axis of the shell, so that only about half of 
its diameter is seen with part of the enormous siphuncle. jS^o trace 
of the test is preserved. 
Horizon. Trenton Formation ( = Bala Limestone Group). 
Locality. Albany, Xew York State. 
Endoceras? Ommaneyi, Salter. 
1852. Orthoceras Ommaneyij Salter, in Appendix to Dr. P. C. Suther- 
land’s Journal of a Voyage in Baffin’s Bay &c., p. ccxxii, pi. v. 
ffi 1(1, 17. 
1853. Orthoceras Ommaneyi, Salter, in a Memoir by Dr. P. C. Suther- 
land, Quart, Journ. Geol. Soc. vol. ix. p. 314. 
1858. Orthoceras Ommaneyi, Ilaughton, Journ. Royal Dublin Soc. 
vol. i. p. 249. 
1859. Orthoceras Ommaneyi, Ilaughton, in M‘Clintock’s ‘Discovery of 
the Fate of Franklin and his Companions,’ Appendix IV. p. 381. 
? 1805. Orthoceras explorator, Billings, Pal. Foss. vol. i. p. 253. 
>8^;. Char. “ This fine large species seems to be frequently met 
with, and will be easily recognized by its large lateral siphuncle, 
and its waved and close septa. It must have been a foot long, and 
one inch and three-quarters wide. The shell tapers slowly and has 
a round transverse section. The septa are placed obliquely, the 
side farthest from the mouth of the shell being that in which the 
large siphuncle is placed, and externally they show a downward 
course on this side. They are very closely placed ; in a specimen 
of an inch and a quarter diameter there are nine in the space of 
barely an inch. The septa are fiattish, and the large siphon is 
placed less than half its own diameter from the edge. It would 
belong to the section Cameroceras.'’ {Salter.) 
llemarJcs. There are two small fragments in the Collection 
labelled with the above name, one of them with a reference to 
Salters figure, but neither of them is the type. They are both 
young examples, one being in fact the apical extremity, and 
measuring not much more than 2J inches in length; the septa are 
very close, there being nine in the space of an inch. 
The other specimen shows the siphuncle in section, and this is 
found to be somewhat less than one fourth the diameter of the shell. 
Billings’s species agrees so closely with this one that there can 
scarcely be any doubt as to the identity of the two species. In the 
former there are said to be about twelve septa to one inch, while in 
Salter’s species we have seen that there are nine, but this was in a 
