210 
AMMONITES nodosus. 
TAB. XCIl.—Fig. 5. 
Spec. Cuar. Involute, depressed, keeled ; volutions 
but little concealed ; radii straight for two-thirds 
of their length, then rising into a small knob, 
from which they extend towards the keel, cury- 
ing upwards, rather distant, with a gentle con- 
cave between them; keel broad, obscure. 
a 
Tue aperture is oblong, broadest towards the front, which 
is rounded; it is one-third the diameter long, and rather 
more than one-sixth wide: the keel, which is plain ex- 
ternally, is crenulated internally or on the cast. , 
From Scarborough, by favor of Mr. Strangewayes; it is 
in a dark brown clay. I think it undoubtedly belongs to 
the keeled division of Ammonites, as it agrees with them 
in general character, although the front is broad, and the 
keel obtuse. 
