74 
AMMONITES corrugatus. 
TAB. CCCCU.—fig. 3. 
Spec. Char. Discoid, carinated and umbili- 
cated, strongly radiated ; carina distinct ; 
radii waved, sometimes furcated, elevated ; 
umbilicus broad, exposing parts of the inner 
whorls ; aperture obovate ; front obtuse. 
Resembling the last, but thicker, with more prominent 
radii, and a broader front. 
From Dundry, with the A. leeviusculus. 
AMM ONITES varicosus. 
TAB. CCCCL1 .—Jigs. 4 and 5. 
Speg. Char. Depressed, costated; inner vo- 
lutions exposed ; carinated when young, 
and furnished with an irregular row of tu- 
bercles upon the inner edges of the whorls ; 
costse curved, large, obtuse, in old shells 
crossing the front; carina distinct; aperture 
oblong. 
In the very young state this Ammonite like many 
others, appears to be nearly plain, but has a distinct 
carina ; as it grows older, a series of crescent shaped, 
nearly close ribs appear on each side of the keel, and a 
few small tubercles arise upon the inner edges of the 
