PE AGH xx Veer 
RHYNCHODUS SECANS, Newb. (p. 47). 
Fie. 1. Left maxillary tooth, showing inside of cutting edge. 
1*. Section. 
2,3. Upper and lower beak-teeth in their relative positions. 
RHYNCHODUS CRASSUS, Newb. (p. 49). 
4. Left inferior tooth, showing inside and triturating surface. Figs. 1-4, natural size. 
Corniferous limestone, Delaware, Ohio. 
CTENACANTHUS VETUSTUS, Newb. 
5,54, Side view and sections. 
Cleveland shale, Sheffield, Ohio, 
286 
