71 
AMMONITES Davcei. 
TAB. CCCL. 
Spec. Char, Depressed; sides nearly flat ; vo- 
lutions exposed, ornamented with numerous 
transverse sulci, and a few distant, obtuse 
tubercles ; aperture nearly orbicular. 
It is of little importance whether this shell be called 
sulcated or ribbed, the sulci and spaces between them 
are so nearly equal. When one coat of the shell is re- 
moved these spaces are flat, as happens in Ammonites 
annulatus, tab. 222, which this much resembles, the 
distant tubercles being the distinguishing mark ; it has 
also fewer whorls ; each tubercle covers, and as it were 
attracts together about four of the sulci. 
Found in the blue Lias of Lyme Regis, in Dorset- 
shire, and preserved by Mr. De la Beche. I have named 
it to commemorate the present intelligent President of 
the Royal Society, as I had formerly done the late 
President. 
AMMONITES Brodicei. 
TAB. CCCLI. 
Spec. Char. Largely umbiiicate, gibbose, cos- 
tated ; cost® radiating, large and numerous, 
terminated upon the sides of the whorls by 
obtuse tubercles, front rounded, plicated ; 
aperture transversely oblong, curved. 
Somewhat resembling Ammonites Brocchii, tab. 202, 
but less gibbose and more strongly marked. The radi- 
ating ribs are slightly curved : from each of the tubercles 
