184 PALEONTOLOGY OF NEW JEESEY. 



Formation mid hcalitij. — The casts which I have described are from the 

 micaceous clays under the Lower Marl Bed, at the pits of the Rev. G. C. 

 Schanck, near Marlborough, N. J., in Mr. Lockwood's collection. There 

 are also two fragments of shell which are apparently of this species from 

 the white limestone nodules at the base of the Lower Marl Bed at Marl- 

 borough, in Mr. Schanck's collection. These latter specimens show a strong 

 posterior umbonal ridge and a thickness of shell which one would scarcely 

 deem compatible with the characters and tenuity of the shell indicated on 

 the casts, and may jjossibly belong to a distinct form. 



Genus LEGUMEN Conrad, 1858. 



(Jour. A. N. Sci., Phil., Vol. IV, p. 277.) 



Legumeu planulatum. 



Plate XXV, Figs. 3 and 4. 



Solemy a planulata Con. J. A.N. S., Phil., 2d ser.,Vol.II,p. 274, PI. XXIV, Fig. 11. Gabb, 



1859, Cat. Invert. Foss., p. 16. 

 Legumen planulata (Con.) Gabb. Synop., p. 133. 

 L. planata (Gabb.) Meek. Check-list Smith. Inst., p. 15. 



L. elUptica and L. appressa (Con.) Gabb. P. A. N. Sci., ]S76, p. 304. 



Comp. L. appressus Conrad. J. A. N. S., Phil., 2d ser., Vol. Ill, p. 325. 



Shell of small size, transversely elongate, about twice and a half as 

 long as high, and elongate-elliptical in outline with the extremities rather 

 sharply rounded. Valves very compressed or flattened, esjDecially so on the 

 posterior part. Beaks small, appressed, not projecting, situated Avithin the 

 anterior third of the length. Surface of the shell marked by proportionally 

 strong regular concentric strise. The internal cast shows a well marked 

 gash l^ehind the anterior muscular imprint, the result of an internal rib 

 similar to that existing in Machcera. 



Li Mr. Meek's list of New Jersey fossils, given in the report for 1868, 

 p. 727, he cites two species of this genus as occurring in the State, but does 

 not mention this one. Mr. Conrad's type of this species was from Monmouth 

 County, New Jersey, and is the only one originally described from this 

 State. Among the fossils from the State which I have examined I have 

 found none corresponding to the figure given by Mr. Conrad of L. elMpticiim, 

 but to L. appressum, which is not figured, it seems to be very nearly related, 



