PLATE LXII. 



Zone of Harjjoceras serpeniinum. 



Fig. 1. Harpoceras exaratum, Yo/mr/ and Bird. Side view, natural size. My 



collection. 



2. — — — Front view of do. do. 



3. — — — Back view of do. do. 



4. — Lythense, — Side view, do. My 



collection. 



5. — — — Back view of same, do. 



6. — — — Front view do. do. 



