I08 NEW YORK STATE MUSEUM 



problematicum. On being worked out it proved to be a large 

 lamellibranch and this has been identified by Doctor Ulrich with 

 his genus Saffordia. A second more fragmentary specimen obtained 

 a year ago by the writer in a bluestone quarry between Schenectady 

 and Aqueduct verifies the actual occurrence of the species in the 

 Schenectady sandstone. 



Description. Shell large, transversely subovate, the height and 

 length nearly as five is to seven. Dorsal margin nearly straight, very 

 gently convex, anterior margin distinctly concave in upper part and 

 moderately convex in the lower; the ventral and posterior margins 

 form one very strongly and evenly rounded curve. Beaks sub- 

 terminal, declining forward, strongly incurved, projecting forward , 

 nearly as far as the anterior extremity of shell ; umbonal ridge very 

 inconspicuous; angular along the dorsal edge. Probably a narrow 

 sulcus on the dorsal slope; ventral and anterior slopes depressed 

 convex. Escutcheon and lunule suggested but not clearly preserve^ 

 in the type specimen. Surface marked with strong concentric folds 

 that are most prominent in the upper half and become fainter on 

 the umbonal ridge and along the anterior and ventral margins. 

 Internal characters not observed. 



Position and locality. In the sandstone of the Schenectady shale 

 at Schenectady. 



Remarks. This species differs by its dimensions from all other 

 Saffordias, which are distinguished by their rather small size. In 

 its general outline, the characters of the beak, etc. it most resembles 

 S. ventralis Ulrich, a Richmond species of Minnesota and 

 Wisconsin. 



Archinacella orbiculata (Hall) 

 PI. 7, fig. 1-6 



Hall (title 3, page 306) has described as Carinaropsis 

 orbiculatus a small patelloid gastropod from the " slates of 

 the Hudson River group, near Waterf ord," which has been obtained 

 by us in the Snake Hill beds of Snake hill and other localities, among \ 

 them also the contorted shales near Waterford, N. Y. The original 

 description of this species reads as follows : 



Suborbicular, apex subcentral, small, slightly inclined; surface 

 finely striated. This species has the form of Orbicula, but the apex 

 is remarkably elevated and no flat valve has been observed. 



A comparison of the two type specimens kindly loaned to us by 

 Dr E. O. Hovey, with the description and the original figures (op. 



