PLATE XXXVIII. 



Zone of Aegoceras Ibex. 



Fig. 1. Aegoceras Valdani, d ' Orbigny. Lateral view, natural size. In collection of 



Mr. Charles Moore, F.G.S., Bath. 



2. — — — Front view of siphonal area do. 



3. Body-chamber with aptychus in situ. My 



collection. 



4. — — Lobes and saddles of this species magnified. 



5. densinodum, Quenstedt. Lateral view, natural size, showing the 



remarkable inflated mouth-border of 

 this species from near Yeovil. My 

 collection. 



6. - — Siphonal area, showing its flatness and 



the lateral position of the short spines. 



