OBTHOCEKATID-E. 
11 
1852. Orthoceras junceum ?, Shumard, in D. D. Owen’s Geol. Suit, of 
Wisconsin, Iowa, and Minnesota, p. 026. 
I860. Orthoceras Junceum, Billings, Geol. of Canada, Appendix, p. 949. 
Sj). Char. ‘‘ Slender, terete-cylindrical, tapering very gradually ; 
septa thin, distant from | to | the diameter ; outer chamber deep ; 
siphuncle small, central ; section circular ; surface finely striated 
transversely.” * * * (Hall.) 
Bemarl's. Besides a well-authenticated example of 0. junceum 
from the Trenton limestone of Watertown, Aew York, I have 
referred also to this species a group of specimens in the Collection 
from the Cincinnati Group of Dubuque Co., Iowa. The matrix in 
which they are imbedded is a sandstone, and the fossils are marvel- 
lously well preserved in it, the nacreous layer as well as the outer shell 
still adhering to them. The slowly tapering, slender, cylindrical 
form, and the surface -markings (fine transverse stride) and small, 
nearly central siphuncle are all in agreement with the characters of 
Hall’s species. 
Dr. Shumard states {he. cit.) that the fossil referred by him to 
0. junceum is larger than Hall’s f. 3, pi. xlvii., and this is the case 
also with the specimens above described. 
Horizon. Trenton Formation and Cincinnati Group ( = Lower and 
Middle Bala ?). 
LoexUties. Watertown, Xew York State ; Dubuque Co., Iowa. 
Fairly well represented. 
Orthoceras multicameratum, Emmons. 
1842. Orthoceratites multicameratus, Emmons, Geol. of Xew York, 
pt. 2, p. 382, f. 93. 
1847. Orthoceratites multicameratuin, Hall, Geol. of Xew YMrk, vol. i. 
p. 45, pi. xi. ft’. 1, a, b, c. 
1803. Orthoceras multicameratum, Billings, Geol. of Canada, p. 194. 
1809. Orthocera-^ multicameratum? , Salford, Geol. of Tennessee, p. 289. 
1875. Orthoceras multicameratum, Xicholson, Pal. of Ontario, p. 30, 
f. 12, «. 
Sp. Char. “ Extremely elongated, slender, very gradually tapering 
to an acute point ; surface apparently smooth, or girt with slight 
undulations ; septa thin, gently arched, distant from a ^ to the 
diameter ; siphuncle a cylindrical ventral tube ; outer chamber very 
deep.” {Hall.) 
This species resembles the 0. tenuiseptum of the Chazy Limestone 
(Arenig ?) in the closeness of its septa, but in the latter these are 
still closer. Of 0. tenuiseptum, however, only fragments have been 
found, and all its characters are not known. 
