290 



NEW YORK STATE MUSEUM 



Ontaria affiliata sp. nov. 



Plate 7, fig. 21, 22 



This shell is a radiate plicate species allied to O. c 1 a r k e i in some 

 respects, differing therefrom in (1) contour, this species being more convex 

 at the umbo and over the body of the valve with steeper slopes anteriorly 

 and posteriorly; (2) direction of plications, which pass radially with slight 

 curve from beak to margins ; (3) character of plications : these are fine, flat, 

 even more numerous at the start than in (). clarkei, simple for one half 

 their length, thence forward rapidly intercalating or splitting, and at the 

 margins all are separated by linear grooves irregularly fasciculated. Faint 

 concentric folds are evident but no concentric lines. 



Habitat. Genesee province; Naples subprovince. The single valve 



showing the above characters is from the soft shales of Parrish gully, 



Naples. 



Ontaria halli sp. nov. 



Plate 7, fig. 23— 24A ; plate 8, fig. 28 



These shells approach very closely Cardiola subarticulata 

 Beushausen ' having from 80 to 100 fine, simple, rounded striae, which 

 become flattened over the pallial region in front and behind and are 

 separated by linear furrows. The surface bears a series of low, broad con- 

 centric undulations and also very fine concentric cancelating striae. The 

 shells from the Naples shales are less convex than the German species 

 referred to, but this may be a casual difference. In outline they are some- 

 what transversely oval or subcircular, narrow across the umbones without the 

 expanded subcircular extremities of associated species. The beak and 

 umbo are prominent, and the general contour of the surface as in other 

 species here described. The character of the surface serves to distinguish 

 the species, being less finely striated than in O. clarkei, and no other 

 associated form carries the combination of radial striations, strong con- 

 centric corrugations and fine concentric striae here present. 



l Op. cit. p. 352, pi. 37, fig. 4. 



