42 



i[ Senate 



OETOmS EMINENS ( n. S.)- 



Pal. N.Y. Vol.iii, pi. 11, f. 7 - 14. 



&IELL circularly subquadrate, wider than high ; ventral valve very 

 convex near the beak, flattened or depressed towards the base ; 

 beak very prominent, projecting much beyond the opposite 

 valve, pointed and slightly incurved : dorsal valve convex in 

 the middle, and depressed almost equally towards the margins ; 

 beak rising but slightly above the hinge-line, with a central 

 depression which is lost before reaching the middle of the valve : 

 hinge-line less than the width of the shell; area large, extending 

 to nearly two-thirds the entire width of the shell ; foramen large 

 and high. Surface finely striated with frequent bifurcations, and 

 curving upwards to the hinge-margin. 

 liocality, Helderberg mountains. 



OeTHIS EMINENS. 



Orthis tubulostriata ( n. s.). 



Pal. N.Y. Vol.iii, pi. 11, f. 1-6. 



Shell subcircular : valves nearly equally convex, depressed near 

 the margin ; ventral valve more prominent towards the beak, 



