133 
AMMONITES complanatus. 
TAB, DLXIX.—fg. 1. 
Spec. Cuar. “Fiat, volutions wholly inserted, the 
inner half marked with numerous indistinct 
transverse undulating striez, the outer portion 
plicated ; umbilicus very small, almost con- 
cealed ; carene slightly convex, its margins 
crenated by the angular terminations of the 
plicee ; aperture sagittate.”’ 
“Tue longest diameter is about 8 inches, greatest thick- 
ness 1°8 inch, width of the outer volution 5 inches. 
“‘ The volutions are thickest near the middle, and gra- 
dually contract into a narrow keel, which at the aperture 
does not exceed 4-tenths of an inch in width, and has an 
elevation or ridge down the centre... . The septa are nu- 
merous, and very foliaceous. 
“ Locality, Hamsey.”’ 
With Mr. Mantell’s kind permission we have figured 
the specimen from which the above description, copied 
from his Geology of Sussex, pages 118 and 119, was taken. 
We know of no other example of the species : it is twice 
the diameter of the figure. The plice do not occur upon 
the outer volution. 
