MIOCENE MOLLUSCA AND CEUSTACEA.- 39 



Genus MODIOLA Lamarck. 



MODIOLA INPLATA. 

 PI. VI, figs. 3 and 4. 



Mytilus inflatus Tuomey and Holmes; Plioc. Foss. South Car., p. 33, PI. xiv, fig. 3; 



Heilprin, Cat. Mioc. Moll, of N. Jersey, Proc. Acad. Nat. Sci. Phil., 1887, pp. 



397, 398, and 402; Tert. Geol. U. S., p. 8. 

 Penia {Mytilus) innata (T. and H.) Conrad; Proc. Acad. Nat. Sci. Phil., 1862, p. 579. 

 Volsella inflata (T. and H.) Meek, Check List Mioc. Foss., i). 7. 



Shell of moderate size aud very oblique, the axis of the body of the 

 valve forming an angle of about 45 degrees with the line of the cardinal 

 border. Hinge line about two-thirds as long as the body of the shell meas- 

 ured from the beak t() the postero-basal angle. Beaks large and inflated, 

 projecting considerably beyond the line of the hinge and distant from the 

 anterior extremity of the shell. Body of the shell inflated, and marked by 

 a very distinct and rather sharp sulcus from the beak to the antero- 

 basal margin, which is somewhat sinuate. Posterior border oblique and 

 the extremity rounded. Surface of the valves marked by pretty strong 

 concentric lines of growth. In the interior the hinge is marked by a thick- 

 ened rib a little within the margin, which gives on the internal cast the 

 appearance of a flattened hinge-plate, sometimes nearly or quite an eighth 

 of an inch wide. There are no teeth or septum beneath the beak, however. 



The shell bears considerable i-esemblance to the recent shell, M. taUpa, 

 of our southern coast, in its general appearance, and might be readily 

 classed with it under the same specific name, so far as can be seen from the 

 two single valves which I have before me. 



Locality: The shells used are from greenish-gray marls and are said to 

 come from Shiloh, N. J. I have seen several fragments of the species and 

 some other casts or partial casts from the harder stony layers of marl at the 

 same locality. Also, several internal casts have been sent me in collections 

 from the dark brown marls near Bridgeton, N. J. The first are from the 

 Academy of Natural Sciences, Philadelphia, and the second from New 

 Brunswick, N. J., and the National Museum at Washington. 



