436 PALEONTOLOGY OF NEW YORK. 



Valves n>oderately convex, a little gibbous in the umbonal region. 



Beaks anterior to the middle, prominent, inclined forward. 



Surface, in the cast, marked by about sixteen or eighteen strong rounded 

 plications, several of which bifurcate toward the margin. There are a few 

 irregular varices of growth indicating the aggregation of the concentric striae 

 and giving a slightly nodose character to the radii. 



One specimen has a length of 30 mm. and a height of 29 mm. 



This species resembles L. curtum, but the radii are stronger and bifurcate. 

 Formation and localities. In the Goniatite limestone of the Marcellus shales, 

 at Cherry Valley and Schoharie, N. Y. 



LUNULICARDIUM OBBICULARE, n. Sp. 



PLATE LXXI, FIG. 24. 



LuniUicardium onuUumf Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 71, fig'. 24. 1883. 



Shell of medium size, sub-orbicular; length and height about equal. Pallial 

 margin regularly curving. Post-cardinal slope obliquely truncate. 



Valves moderately convex, scarcely gibbous above. 



Be.aks sub-central, slightly inclined forward. 



Surface marked by about thirty low rounded plications, which become a 

 little obscure on the upper anterior margin ; interspaces narrower than the 

 radii. Also marked by fine undulating concentric striae. 



The specimen described has a length and height of about 26 mm. 



This species resembles, in its surface characters, L. ornatum, but the shell is 

 shorter, the posterior truncation also shorter, the radii proportionally larger 

 and rounded, and the beak is less attenuate. 



Formation and locality. In the Marcellus shale, Bloomfield, Ontario county, 



N. Y. 



