NAPLES FAUNA IN WESTERN NEW YORK, PART 2 243 



Dimensions of the only specimen found : hight 13 mm, length 9 mm. 

 Habitat. Genesee province ; Naples subprovince. From the lower 

 Portage falls of the Genesee river gorge. 



Lunulicardium (Prochasma) parunculus sp. nov. 



Plate 3, fig. 17-20; plate 4; fig. 14 



Cf. Prochasma dilatatum Beushausen, Lamellibr. des rhein. Devon. 1895. 

 p. 376, pi. 28, fig. 8, 9 



Shells of rather large size, obliquely ovate, beak nearly central or lying 

 just behind the axial line. Behind the beak the margin is usually some- 

 what incurved, and its surface bears one or two short ribs; thence the 

 curve is abruptly outward, and a rounded angle of nearly 90 is formed, at 

 the turn to the nearly straight postlateral margin. Over the. basal margin 

 the curve is broad, rising obliquely to the extremity of the sicae, where it 

 makes an angle of about 6o°. The sical margin is straight, arched, and is a 

 little longer than one half, the hight of the valve. 



Surface usually with concentric lines and low wrinkles or festoons. 

 Exceedingly fine, radial, filiform lines are visible on internal casts and 

 doubtless pertain to the inner rather than the outer shell layers. 



Dimensions. Hight of an average specimen 29 mm, length 23 mm; 

 length of sical margin 19 mm. 



Observations. The smaller of Beushausen's specimens of P r o - 

 chasma dilatatum approach this shell very closely in all details. 

 We should be disposed to assign the latter to that species, were it not 

 for the difference suggested by the larger forms included under that name. 



Habitat. Genesee province ; Naples subprovince. Parrish gully and 

 other outcrops of the shales, Naples N. Y. 



Lunulicardium beushauseni sp. nov. 



Plate 3, fig. 12, 13; plate 4, fig. 15 



Shell below medium size, subcircular in general outline, beak nearly 

 central or slightly posterior. Posterior margin incurved beneath the beak, 

 bending outward in a nearly semicircular curve to the basal margin, which 

 continues the same curvature but with a broader expansion over the 



