■i^ r.vr..i:oNTOLOGY or omo. 



lateral denticles on either side, all striated. Central cone slightly 

 recurved, section above nearly circular, below, posterior face flattened, 

 giving lateral angles. 



Tliis species is about equal in size to Gladodus Pattersoni, but may 

 1)6 readily distinguished from that by its lateral denticles, less curvature 

 anil striated surfaces. 



Formation and Locality. Cuyahoga Shale over Berea Grit, Berea, Ohio. 



Cladodus coNciNNtrs (n. sp.). 

 Plate LVIII., Fig. 8. 



Teeth small, about 6 lines in height and breadth ; base very narrow, 

 boat-shaped, with pointed extremities ; central cone much compressed 

 with sharp edges, posterior face flat, anterior rounded, both strongly 

 striated ; lateral denticles two pairs, both striated, external pair the 

 larger, and divergent. 



This small species is noticeable for its compressed, double-edged, and 

 strougly-sti'iated cone, its divergent lateral denticles, and narrow pointed 

 base. These characters will serve to distinguish it from any others with 

 wliich it may be compared. It is not unlike in general appearance 

 •C. 3ygo])us, described in the Illinois Geological Eeport, Vol. II., p. 25, 

 Plate I., Figs. 9, 9 u, 10, but in that species the base is distinctly yoke- 

 shaped — i. e., arched on one side, excavated on the other — and the pos- 

 terior face of the cone has a deep furrow at the base. 



This is the most elegant in form and most highly ornamented of all 

 the species of Gladodus yet found in Ohio, and the specific name given 

 it was chosen to indicate this. 



Formation arid Locality : Huron Shale ; valley of Black River, Lorain County. 



Gladodus parvulus (n. sp.). 



Plate LVIII., Figs. 9, 9 a. 



Teeth very small, and exhibiting two forms ; the larger 4 lines high 

 and broad ; crown compressed and ancipital ; summit very tapering and 

 acute; anterior face rounded; posterior flattened, often slightly keeled 

 above, deeply excavated below ; both faces toward the base having tine, 

 somewhat interrupted and irregular striae ; lateral denticles two, flattened, 

 triangular, divergent ; base yoke-shaped, posterior margin deeply sinused, 

 under surface concave. 



