136 PALEONTOLOGr OP NEW JBRSBT. 



or less rounded, and in old individuals sometimes distinctly rounded; casts 

 showing a small umbilical perforation, but the axis probably solid in the 

 shell; volutions probably seven or eight, but in the casts the upper ones 

 are usually absent and seldom show more than four or four and a half; 

 one small specimen retaining the upper whorls, to the number of four and 

 a half, measures only five-eighths of an inch in diameter. This one, if con- 

 tinued below to the size of xthe larger one figured, would possess at least 

 eight volutions; whorls obliquely flattened on their surfaces in the direc- 

 tion of the spire, with only a small portion of their edges rounded or ver- 

 tical, and the surface deeply and abundantly scarred by the cicatrices of 

 foreign substances which have been attached to the surface of the shell 

 during life ; apertm'e compressed, transversely ovate or trapezoidal, and the 

 outer margin much prolonged 



This seems to be a not uncommon shell at some of the localities of the 

 Lower Marls, but is seldom found except in fragments ; the upper portion 

 nearly always being absent, and the cast often looking as if these parts had 

 been filled up or absorbed, rather than that the casts had been mutilated. 

 I presume the upper portion of the whorls were in many cases cut off by 

 partitions deposited across them, which would give the casts their present 

 appearance. 



Formation and locality: In the Lower Green Marls at Upper Freehold; 

 in the brown mai'ly layers of the same horizon near Burlington; also at 

 Crosswicks Creek and at MuUica Hill, New Jersey. The type of the 

 species was from Prairie Bluff, Alabama, from which locality I have seen 

 numerous specimens. 



Genus ENDOPTYGMA Gabb. 



Endoptygma umbilicata. 



Plate XVII, Fig. 30. 



Phorus umbilicatus Tuomey: Proc. Acad. Nat. Sci., Phila., 1855, p. 169. 

 Endoptygma umbilicata (Tuom.) Gabb: Proc. Acad. Nat. Sci., Phila., 1876, p. 303. 



Shell rather below a medium size, spire broadly conical, with an 

 apical angle of about 80°, and composed of about four volutions; base 

 flat or slightly concave, and in the cast showing a small open umbilical 



