PLATE XUII. 



PAGE. 



Figs. 1-5. Sectional view of mandible of Dinichthys Terrelli 607 



1. Showing outer spongy and inner dense bone. 



2. Section of outer or spongy bone showing Haversian canals and lacunae. 



3. Part of section 1. 



4. Section of inner dense bone showing small Haversian canals and lacunae with 



larger canalicules. , 



5. Part of section 4 showing canaliculi traversing the bone. 



Fig. ha. Cladodus 619 



5a. Showing teeth in position in jaw and a large coprolite in the body of the fish. 



Fig. 6. Cladodus rotundiceps 618 



6. A small shark only about 30 inches long with less strongly marked pectorals and 



showing the membranous expansion at hinder end of body and the bases of 

 two rays of the caudal fin. 



