LAMELLIBEANCHIATA OF THE LOWEE MAELS. 141 



sharply defined, being somewhat angular on the crest, with rounded de- 

 pressions between, and are of nearly equal strength on all parts in some 

 individuals, while on others they gradually increase in number and fineness 

 toward the anterior end. 



This species may be readily distinguished from L. inflata, herein de- 

 scribed, by its longer forai, less inflated valves, smaller beaks, and strongly 

 marked ribs. It differs from L. elegantula {Cardium elegantula Romer, Kreid. 

 von Texas, p. 48, PL III, Fig. 5) in being a little more ventricose, with less 

 distant ribs, and is without the broad flattened interspaces figured as exist- 

 ing in that species. Mr. Gabb, however, in his Synopsis cites them as iden- 

 tical. 



Formation and locality,— hi the Lower Green Marls at Holmdel, New 

 Jersey, and also in the white limestone near that place. It also occurs at 

 Burlington, New Jersey, at the same horizon. The species is also quite 

 common in the white limestones of the Cretaceous at Prairie Bluff", Ala- 

 bama. In the collection of the American Museum of Natural History in 

 New York there is a shell from Eufaula, Alabama, which closely resembles 

 this species, except that it has not been quite so much inflated, and the ribs 

 are less prominent, while the posterior end of the shell is entirely destitute 

 of radiating costse for a much wider space than has been the case with the 

 New Jersey specimen. 



Leiopistha elegantula. 

 Not figured. 



Cardium elegantula Ecemer. Kreid. von Texas, p. 48, Tab. Y, Fig. 6. 

 Fragilia elegantula (Eoem.) Conrad. J. A. K S., Phil., Yol. lY, p. 275. 

 Fapyridea elegantula Gabb. Synopsis, pp. 106 and 162. 



Mr. Conrad, in the Journal of the Academy of Natural Sciences, Phil- 

 adelphia, 2d series. Vol. IV, p. 275, cites this species as coming from New 

 Jersey, and gives it as one of the evidences of the synchronysm of the 

 Tippah County, Mississippi, and Eufaula, Ala., beds with the Lower Green 

 Marls of the New Jersey deposits. Among the specimens observed from 

 New Jersey there are three distinct species of this group of shells, and of L. 

 jorotexta, a variety possessing very much finer ribs than the normal form, the 



