48 PALAEONTOLOGY OF OHIO. 



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

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

 giving lateral angles. 



This species is about equal in size to Cladodus Pa'tersoni, but may 

 l)e readily distinguished from that by its lateral denticles, less curvature 

 and striated surfaces. 



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



Cladodus co]^^ci]srNUs (ii. 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 

 strongly-striated cone, its divergent lateral denticles, and narrow pointed 

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

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

 C. zygojniSy described in the Illinois Geological Report, Vol. II., p. 25, 

 Plate I., Figs. 9, 9 a, 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 Cladodiis yet found in Ohio, and the specific name given 

 it was chosen to indicate this. 



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



Cladodus parvulus (n. sp.). 



Plate LVIIL, 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 fine, 

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

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

 under surface concave. 



