88 



PALJiONTOLOGY OF NEW-YORK. 



This shell has the form of Nucula, but the hinge-line shows no teeth or crenulations. In 

 the cast the cardinal line is smooth, and the surface presents only the mark of a single strong 

 muscular impression at the anterior extremity, which is not prominent enough in the figures. 

 In some specimens there is the appearance of a muscular fold near the posterior extremity, 

 but it is not sufficiently defined to be reliable. 



Fig. 3. This specimen, though differing to some extent in form, I have referred to the same 

 species. It retains the shell, which is faintly striated, the beak remarkably elevated, 

 and the anterior extremity abruptly rounded. 



Fig. 12 a, b. The casts of opposite valves of specimens nearly of the same size. 



Fi^. 12 c. The cast of a large individual, showing several prominent folds parallel to the lines 

 of growth. 



Position and locality. The specimen fig. 3 was found in the shale below the ore bed in 

 Wolcott. The casts 12 a, 6, r, occur in a shaly sandstone near the base of the group, associated 

 with {Agnostis) Beyrichia, in New-Hartford, Oneida county. [State Collection.) 



Several other species of acephalous moUusks occur in the shales and sandstones of this group ; 

 but the specimens which I have collected are not sufficiently perfect, or well marked, to enable 

 me to draw specific distinctions which would be useful in identifying them hereafter. 



