CEPHALOPODA OF THE CRETACEOUS MARLS. 263 
an abruptly increased vertical height to the neck or straight part to the 
base of the aperture; the line of which is exactly rectangular to it, and 
slightly infolded on the edge; surface of the shell marked throughout by 
transverse undulations, small on the inner coils and frequently bifurcating, 
but directed straight across the shell from the ventral line. On the hori- 
zontal portion they are much stronger and coarser, and above the outer 
geniculation they again become as fine and close as on the inner coils. 
The shell is further ornamented by two lines of nodes along the sides; the 
outer lines the smallest on the outer chamber, the other line imperceptible 
on the coiled part. At the angle of the outer geniculation there exists the 
largest node of all and outside of it two or three smaller ones. Septa 
somewhat closely arranged, but rather simple in structure, composed of a 
dorsal and three lateral lobes; dorsal lobe with four divisions, two on each 
side of the central line, the first division doubly clavate, the other with 
four rounded projections on the outer side; second lobe, or first lateral lobe, 
with two main divisions widely separated, each of which is deeply bifur- 
cate, with slight lobations near their extremities; second lateral lobe small, 
clavate with a trilobed end; third lateral lobe only about half the size of 
the second, but of similar form; first sinus much wider and larger than the 
first lateral lobe, with four double divisions (one of which in the septum 
drawn is imperfect); second sinus with two double or bilobed divisions; 
third sinus simply bilobed, and the third simple; the septum figured and 
its details here given is the second from the outer chamber of Dr. Morton’s 
figured specimen and gives the details of course much more developed than 
would a septum at an earlier stage of growth. 
Dr. De Kay described this species originally from an imperfect cast of 
the outer chamber of only medium size, which appears to have been the 
property of the New York Lyceum, and was from Delaware. I have 
before me at the present time a similar specimen of somewhat smaller size, 
having only about half the diameter of the one figured, but showing the 
same features on a reduced seale. The species is peculiar among all the 
American Scaphites in the rapid lateral increase in size of the central por- 
tions of the outer volution, which gives it a peculiar form and appearance 
which will readily distinguish it. 
