MARYLAND GEOLOGICAL SURVEY 329 



remote from the basal margin; outer surface ornamented with fine, 

 regular, close set concentric grooves, the narrow ridges between being 

 rounded. 



Length, 6.25 mm.; height, 5.1 mm.; diameter, 1 mm. 



Occurrence. — ^Calvert Formation. Plum Point. 



Collection. — Cornell University. 



Erycina speciosa n. sp. 

 Plate LXXXVIII, Fig. 5. 



Description. — Shell almost elliptically rounded, save for the slight 

 projection of the beak; anterior end slightly longer; anterior basal mar- 

 gin slightly prolonged before curving upward; shell flattened with a 

 lenticular slope or surface curvature near margins; teeth very strong 

 and prominent, projecting; exterior smooth; interior polished. 



Length, 4 mm.; height, 3.2 mm.; diameter, 0.9 mm. 



Occurrence. — Choptank Formation. Governor Eun. Calvert For- 

 mation. Plum Point. 



Collections. — Maryland Geological Survey, U. S. National Museum. 



Subgenus PSEUDOPYTHINA Fischer. 

 EkYCINA (PsEUDOPY^THINA?) AMERICANA Dall. 



Plate LXXXVII, Figs. 14, 15. 



Erycina {r^eudopyiliina ?) americann Dall, 1900, Trans. Wagner Free Inst. Set., vol. 

 iii, pt. V, p. 1146, pi. xliv, tigs. 21, 25. 



Description. — " Shell large, moderately convex, inequilateral, rounded 

 at both ends, the posterior side shorter; beaks low, surface sculptured 

 only with rather conspicuous incremental lines; anterior dorsal margin 

 nearly parallel with the base, posterior dorsal margin arcuate; hinge- 

 margin narrow, feebly channelled, edentulous, adductor scars small, 

 narrow, high up; pallial line wide and radially striated." Dall, 1900. 



Length, 16 mm.; height, 10.5 mm.; diameter, 7 mm. 



Occurrence. — Calvert Formation. " Calvert Cliffs " {■= Plum 

 Point?), (P>urns). 



Collection. — U. S. National Museum. 



