131 
ORTHOCERA eonxesb 
TARo LX. — Figs. 1, 2 3 and 3\ 
Spec. Char. Shell long-conical, aperture oval, a 
little wider one way than the oilier, smooth, 
chambers numerous, increasing in depth by 
age; siphuncle nearly touching one of the 
sides, small. 
The septa have even margins and regularly concave six?* 
faces, they are very thin and twice as distant from each 
other at the broadest end of the shell; the siphuncle is oval* 
about half a line wide. 
These figures exhibit specimens from the Alum Clay at 
Whitby, presented to me by the Marchioness of Bath. 
Fig. 1 is a dark Iron clay stone, the shell chiefly Carbonate 
of Iron. The edges of the septa have something like a 
double margin, or a little sulcus, which is occasionally 
apparent within the shell. Fig. 2 has the shell of a lighter 
tint with some signs of Pyrites and the remains of the 
pearly lustre in the division ; it is also less conical, and 1 
should consider it as the narrow continuance of the same 
species. Fig. 3 shows the convex side of gm of the septa 
with the siphuncle near the edge. 
/ 
