LAMELLIBEANOHIATA FROM THE EOCENE MARLS. 231 



ASTARTIDiE. 



Genus ASTARTE Sowerby. 

 Astarte castanella, n. sp. 

 Plate XXX, Figs. 1 and 2. 



Crassinaf veta Conrad. Am. Jour. Conch., Yol. Y, p. 41, PL I, Fig. 5. 



Not Astarte veta Conrad. Am. Jour. Conch, Vol. lY, p. 279, PI. XX, Fig. 4, or Yol. Y, 



p. 227. 



Mr. Conrad describes this species in the following words: ^* Triangular, 

 inequilateral, convex; posterior dorsal margin straight and oblique; anterior 

 extremity angular and situated much above the line of the ventral margin, 

 which is crenulated within ; cardinal pit under the apex of the left valve, 

 triangular, wide, oblique. (Cast.) Locality, Shark River, N. J." 



I have seen only casts of this species, and do not think it has been 

 recognized under any other form. There are two forms associated with each 

 other so nearly ahke that it is somewdiat difficult to distinguish between 

 them; yet I believe them to form two distinct species. One of the marked 

 features of this one is its crenulated basal mtirgin, which is the only feature 

 that would enable one to say to which Mr. Conrad's description applies. 

 The form is more transverse than that of the other, sometimes becoming 

 almost elliptical in outline inside of the impression of the beak and hinge- 

 plate. The posterior end is also more distinctly truncate, wdth a slight uni- 

 bonal angle, and the anterior end somewhat longer proportionally. The 

 margin of the valve is strongly, and for so small a shell almost coarsely 

 crenulated, while that of the other is smooth. 



This being a true Astarte, and Mr. Conrad having previously described 

 an Astarte veta in Vol. IV, Am. Jour. Conch., p. 279, and Vol. V, p. 227, 

 his specific name veta cannot stand, consequently, from its very close resem- 

 blance to the recent A. castanea, I change it to A. castanella. 



Formation and locality. — In the top layer of the Upper Green Marls 

 (Eocene) at Shark River, Farmingdale, and Squankum, New Jersey. 



