168 
AMMONITES biplex. 
TAB* CCXCIIL— Figs, 1 and 2* 
Spec. Char. Discoid; volutions exposed, costated : 
costae numerous, small, split over the front : 
sides depressed, aperture oblong-. 
V olctions five or six, the numerous costse are nearly 
straight, elevated and obtuse, a little before it passes 
over the front each is divided into two branches, equally 
thick with the undivided rib ; the oblong aperture is 
narrowest near the front which is round ; the external 
and internal surfaces do not differ. 
This Ammonite occurs in a mixture of Clay with 
Septaria and Clalk Boulders, that extends over a great 
part of Suffolk. Fig. 2 is from Barrow, given me by 
Mr, Barnes, of Norwich. 
