PLATE LXIX. 



Zone of Aegoceras Henleyi. 

 Fig. 1. Lytoceras lineatum. Side, natural size. My collection. 



Zone of Aegoceras Ibex. 



2. Aegoceras Valdani, d'Orbigng. Side view, natural size. My collection. 



3. — — — Back view, do. 



4. — — — Lobe-line, magnified. 



Zone of Aegoceras Jamesoni. 



5. — PETTos, QuenstedL Side view, natural size. My collection. 



6. — — — Siphonal area and lobe-line, do. 



