GASTROPODA— BELLEROPHONTIDJE. 



609 



trie and curved forward, radiating striae fine, concentric growth- 

 lines and occasionally wrinkles occur. 

 Chazy of Montreal and New York. 



Fig. 812. Scenella mentrealense, 

 X2. (After Raymond.) 



Fig. 813. Scenella montrealense, 

 X 2. (After Raymond.) 



VIII. Lepetopsis Whitfield. 

 Broadly oval, low conical shells with subcentral apex, growth 

 lines, and more rarely radiating lines. Muscular impression horse- 

 shoe-shaped, open in front. Mississippic-Carbonic. 

 24. L. levettei (White). (Fig. 814.) Mississippi. 



Fig. 814. Lepetopsis levettei. a, perfect shell ; b, with apex removed, showing im- 

 pression of muscular area ; c, a more elongate form ; d y side views of the two forms 

 superposed. (After Whitfield.) 



Nearly oval, conical, beak slightly excentric, anterior and pos- 

 terior slopes slightly different ; growth lines somewhat lamellose, 

 radiating striae obscure. 



St. Louis group of Indiana. 



Family Bellerophontid^e M'Coy. 



IX. Cyrtolites Conrad. 



Shells coiled in median plane, regularly enlarging, angulated or 



carinated laterally and on dorsum, aperture with or without 



median notch. Ordovicic. 



25. C. ornatus Conrad. (Fig. 815, a, b.) Ordovicic. 



