LAMELLIBEANCHIATA OF THE LOWER MARLS. 55 



to Camptonectes, but does not mention it as being the same as his hellis- 

 culptus, about which I think there can be no doubt. In the younger stages 

 of growth the shell is much more elongated, and this feature may have 

 induced him to retain, his specific name for the smaller shell which he 

 described. 



Formation and locality. — Mr. Conrad cites it from Haddonfield, N. J. 

 The specimens in the State collection are from Holmdel, N. J., both local- 

 ities being- in the Lower Green Marls. Specimens borrowed from the collec- 

 tion of the Academy of Natural Sciences, Philadelphia, come to me with- 

 out locality marks. 



Camptouectes parvus, n. sp. 

 Plate VIII, Figs. 1 and 2. 



Shell quite small, the only specimen observed measuring only about 

 three-tenths of an inch in height. Outline subcircular and (the left valve) 

 convex, moderately elevated on the umbo and somewhat regularly declining 

 in convexity, toward the front; anterior auriculation proportionally large and 

 vertically striated with lamellose striae parallel to the anterior margin. 

 Surface of the shell polished and mai'ked with numerous interrupted 

 impressed striae, the spaces between the striai being flattened and crossed 

 by very faint lines of growth. 



Only a single individual of this species has come under my observation. 

 The shell presents the features in its external appearances of the Jurassic 

 forms of the genus, as they occur at the west, and is the only individual 

 from New Jersey that I have seen which possesses the peculiar impressed 

 striae so characteristic of those forms. It, however, wants the punctures 

 that are present in the bottom of the striae of those, and in this respect 

 diflFers very materially. It also differs in its very small size and greater 

 convexity. It is possible that it may not be an adult shell, but the character 

 of the striae is sufficient to distinguish it even should it be found of larger 

 growth. 



Formation and locality. — In a band of clayey marl of the Lower Bed^ 

 at Freehold, New Jersey. 



