MOLLUSCA. 633 



ridge is usually rounded, while in the shell itself it is often slightly- 

 angular. Surface of the shell marked with regular concentric 

 lines, which are very fine in the young shells, becoming much 

 stronger with the increased size of the shell. In the larger shells 

 the surface markings seem sometimes to have been nearly or 

 ■quite eroded, leaving the shell nearly smooth. 



Remarks. — This is a common species in certain localities in 

 New Jersey, especially in the Cliffwood clay and the Wenonah 

 sand. . Specimens from different localities exhibit considerable 

 variation, especially in the distinctness of the concentric surface 

 markings. The smaller and younger individuals possess these 

 markings most clearly, but in the larger examples they seem 

 usually to have been more or less eroded. 



Formation and locality. — Cliffwood clay, Cliffwood Point 

 (105, 185), near Matawan (107, 186, 189) ; Merchantville clay- 

 marl, near Matawan (loi), near Jamesburg (139, 141) ; Wood- 

 bury clay, near Matawan (103), near Haddonfield (164, 165, 

 183) ; Marshall town clay-marl, near SiwedesborO' (177) ; Weno- 

 nah sand, near Crawfords Corner (126), near Marlboro. (130) ; 

 Red bank sand, Shrewsbury River (119), Red Bank (116), near 

 Middletown (112) ; Tinton beds, Beers Hill cut, south of Key- 

 port (129^). 



Geographic distribution. — New Jersey, Geofgia, Alabama, 

 Mississippi, Texas. 



Cymbophora tellinoides (Whitfield). 

 Plate LXXI., Fig. 22. 



1886. Veleda Tellinoides Whitf., Pal. N. J., vol. i (Monog. 

 U. S. G. S., vol. 9), p. 173, pi. 23, fig. 23. 



Description. — ^"Shell large for the genus, the cast, the only 

 form under which it is known, being fully one and a quarter 

 inches in length ; form transversely ovate, largest at the anterior 

 end, and two-thirds as high as long. Valves depressed convex 

 with small appressed beaks and a slight angulation passing from 

 the beak to the posterior extremity, forming a narrow posterior 

 cardinal slope. Surface, as shown on the cast, marked by fine 



