162 PALEONTOLOGY OF NEW JEESEY. 



serving the shell, which I suppose to be one of the same species, have the 

 same general form, with very thin shells, smooth or only marked with fine 

 concentric lines and occasional varices of growth, all are imperfect at the 

 beaks and hinges. The cardinal margins are very sharply and deeply inflected, 

 but none of the hinge features are preserved so as to be determined. 



I find no description or figure answering to this species. The speci- 

 men used for illustration I found in the cabinet at Rutgers College, marked 

 "'' Mysia gibbosa Gabb " in what was supposed to be Mr. Gabb's own hand- 

 writing. But the specimen dififers very materially from Mr. Gabb's figure 

 cited under Tenea pinguis Con., and also from the specimens which I have 

 referred to that species, in being much less gibbous, less erect, rather more 

 transverse, and in having the postero-cardinal margin in the cast even more 

 strongly inflected. The shell is, I think, as nearly a true Bosinia as any 

 found in the Cretaceous formation,, and certainly does not belong to the 

 genus Mysia Leach, as it has a deeply sinuate pallial line, which that genus 

 does not admit, and it appears to possess all the requisite features of Dosinia 

 so far as they can be made out. 



Formation and locality — In the Lower Green Marls at Burlington and 

 Freehold, New Jersey, received, as indicated on the labels, from S. J. Ger- 

 main and D. Bishop; also in the cabinet of the American Museum of Nat- 

 ural History. The specimen preserving the shell, identified as the same 

 with the casts, are from Upper Freehold, New Jersey, from collections 

 made by Dr. Bruere. 



Dosinia ? erecta, n. sp. 

 Plate XVIII, Figs. 17-20. 



Shell small, less than an inch in height, and quite erect, being nearly 

 equilateral and ovate in outline, the widest part opposite or below the 

 middle, with appressed valves, most gibbous near the umbones, the beaks 

 small, erect, and moderately approximate. Cardinal margins of the valves 

 strongly and sharply inflected, most strongly and largely so on the ante- 

 rior side. Surface of the valves marked only by fine irregular concentric 

 lines of growth, and the substance very thin and fragile. Hinge charac- 

 ters unknown. Muscular imprints small and obscure, and the pallial line 

 unknown. 



