82 
AMMONITES Plicomphalus. 
TAB. CCCLIX. 
Spec. Char. Discoid, umbilicate; umbilicus 
large, with 8 or 10 diverging, rather sharp, 
protuberances around it ; front rounded, 
plain. 
Aperture ovate ; about 3-7ths the diameter of the last 
whorl long ; narrowest towards the front ; the emi- 
nences about the inner edges of the volutions are wide, 
and extend over a part of the sides : the umbilicus is 
large, equalling half the length of the mouth. 
Presented to me by Mr. Weir, who found it in a 
very mutilated state in the harder part of the Sand- 
stone stratum, at Bolingbroke, Lincolnshire. 
