3 
AMMONITES Calloviensis. 
TAB, CIY. 
f 
Spec. Char. Involute,, subumbilicate, rather de- 
pressed; volutions about five, three-fourths 
concealed; front fiat; radii small, very numer- 
ous, alternately one long and from two to five 
short, obscure in the latter whorls of old 
shells ; ' aperture orbicular when young, deltoid 
with the angles truncated when old. 
Age makes a great difference in the form of the whorls of 
this shell, the young ones being roundish, and having 
numerous sharp radii in sets, composed of one long one 
very prominent at the commencement, and from two to five 
about two-thirds the length, and all passing over the front* 
The outer whorls of full grown shells are triangular, the 
two inner angles being truncated, so as to give the shell an 
umbilicate appearance; the surface is largely undulated, 
wrinkled near the back, and has many irregular striae in 
the place of radii: the inner surface differs from the outer 
only in the larger whorls being free from striae and losing 
the radii sooner. 
Found in a more or less mutilated state very abundantly 
in the shelly Limestone at Calloways or Kellaways Bridge. 
I have received specimens from many kind friends. Fig. 1 
in the plate was sent me by my friend Mr. Salmon of De- 
vizes, and I picked up the specimen from which Fig. 2 is 
