238 NEW YORK STATE MUSEUM 



Lunulicardium finitimum sp. nov. 



Plate 2, fig. 17, 18 



Shell rather small and narrow. The lateral margins are long, and 

 approach each other at a small angle, so that the aspect of the valve is 

 highly acute. The sical margin extends for more than one half the entire 

 length of the shell, while the anterior edge slopes at very nearly the same 

 angle as the posterior, with a gentle outward curvature. The apparent 

 apical angle is about 55 . The basal margin is regularly curved, the curva- 

 ture being that of the extremity of an ellipse. 



Surface gently and regularly convex ; abruptly deflected on the sical 

 margin. The ornamentation consists of very minute, simple rounded or 

 filiform radial lines, becoming broader and flat. These number over the 

 body of the valve six to 1 mm ; 70 to 90 over all. They are crossed and 

 crenulated by exceedingly minute concentric lines. Near and at the lower 

 margins of the valves the radial ornament is interrupted or extinguished by 

 the moderately strong concentric striae. 



The observed specimens of this rare and well characterized species are 

 two right valves, the larger having a hight of 23 mm, and its greatest 

 length, lying at one third the hight from the lower margin, is 14 mm. 



Habitat. Genesee province ; Naples subprovince. Parrish gully, 



Naples N. Y. 



Lunulicardium sodale sp. nov. 



Plate 2, fig. 22 



This is a shell having the acuminate form of L. f i n i t i m u m, but it 

 shows somewhat greater curvature along the sical margin ; still the apical 

 angle, relative length of the anterior and posterior margins, curvature of 

 the lower margin, width over the pallial region, and convexity of the valves 

 are essentially as in the preceding species. The specific distinction is 

 found in the character of the surface ornament, which consists of radial 

 plications very much larger than in L. finitimum, continuous and 

 simple, flattened on top and separated by furrows as wide as the ribs. At 

 about the middle of the valve there are four of these in the width of 1 mm, 



