- eo 
AMMONITES rhotomagensis. 
TAB. DXV. 
Spec. Cuar. Discoid, radiated, umbilicated ; inner 
whorls partly concealed ; radii about 20, fur- 
nished with three short tubercles upon the 
front, and two more or less elevated upon each 
side ; whorls thick, with flattish sides ; aper- 
ture oblong. 
Syn. Am. rhotomagensis. Cuv. & Brongn. Env. de 
Paris, p. 83. t. 6. f. 2. 
Am. sussexiensis. Mantell, Geol. of Sussex, 
p.114. t. 20. f. 2. and t.21. fig. 10. 
eeeeeee 2”: *< Seal 
In the centre of the rounded front of this Ammonite 
is a row of tubercles, one placed upon each rib; on 
each side. of this is another similar row: these, toge- 
ther with the flattened sides and wide umbilicus, are 
the distinguishing characters; the other two rows of 
tubercles are very variable, the outer one often ri- 
sing into obtuse spines. When these tubercles are in- 
conspicuous, it bears a strong resemblance to A. Man- 
