EXPLANATION OF PLATE XXXVIII. 



GERVILLIOPSIS ENSIFORMIS (Conrad) p. 421 



1. A nearly complete left valve. 



2. Internal view of a less complete valve. 



Marshalltown clay-marl; Woodbury. 



3. View of a large, imperfect internal cast. 



Marshalltown clay-marl?; Woodbury f 



IXOCERAMUS PROOBLIQUA Whitfield, p. 428 



4. The type specimen. 



Xavesink marl; Holmdel. 



IXOCERAMUS ? PEROVALIS Conrad. 



5. View of the right side of an internal cast. The type speci- 



men. (After Whitfield.) 



958 



