432 PALEONTOLOGY OF NEW YORK. 



Pararca neglecta, n. sp, 



. PLATE LXX, FIG. 13. 



In part CardMa transversa. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 70, figs. 12- 



15. 1883. 



Shell small, broadly sub-elliptical ; length one-third greater than the height ; 

 basal margin regularly curved. Posterior extremity broadly rounded. Car- 

 dinal line straight, about half the length of the shell. Anterior end short, 

 regularly rounded below the lunule. 



Valves depressed-convex below, becoming moderately convex in the umbo- 

 nal region, somewhat flattened in the middle below the centre. 



Beaks at about the anterior third, low, rounded, rising but little above the 

 hinge-line. Umbonal slope undefined. 



Surface marked by numerous fine rounded radii, which are much stronger 

 on the anterior end. Interspaces much narrower than the radii. Entire 

 surface also marked by strong, regular, undulating concentric lamellose striae. 



The specimen described has a length of 23 mm. and a height of 16 ram. 



This species is distinguished from P. transversa by its broader and less gib- 

 bous form, coarser radii, coarser and regular concentric striae, and undefined 

 umbonal slope. 



Formation and locality. In the sandstones of the Waverly group, at Mead- 

 ville, Pa. 



Pararca erecta. 



PLATE LXX, FIG. 16 ; AND PLATE XCIV, FIGS. 20, 21. 

 Cardiola erecta. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 70, fig. 16. 1883. 



Shell of medium size or larger, sub-rhomboidal ; length and height nearly 

 equal ; basal margin rounded, abruptly recurving at the post-inferior extrem- 

 ity. Posterior extremity gently rounded or nearly vertically sub-truncate. 

 Cardinal line short, less than half the length of the shell. Anterior end 

 short, margin nearly vertical, gently curviujg to the basal margin. 



