MOLLUSCA. 801 



marked by from 8 to n strong spiral ridges, leaving a plain 

 space at the base of the shell equal in width to that of two of the 

 ridges; surface marked also by somewhat more distant, trans- 

 verse, broadly rounded ridges, which are nodose at the points of 

 junction with the revolving ridges. 



Remarks. This species is apparently restricted to the fauna of 

 the Merchantville clay. It may be easily recognized by its 

 low spire, its surface markings, and by the strong columellar fold 

 situated just within the umbilical margin. The type of the species 

 is a large example, and has the markings more strongly, impressed 

 upon the surface of the cast than is usually tr^e case. The speci- 

 men which Whitfield has described as Pyropsis naticoides must 

 be referred to this same species, and this specimen perhaps rep- 

 resents more nearly the usual form of the species. The shell 

 which has been described as Turbinopsis plicata is another closely 

 allied shell, certainly congeneric, although it is probably a distinct 

 species characterized by a somewhat higher spire and a broader 

 umbilicus. 



Formation and locality. Merchantville clay, Lenola (163). 



Geographic distribution. New Jersey. 



Morea plicata (Whitfield). 



\ 

 Plate XCVIIL, Figs. 16-17. 



1892. Turbinopsis plicata Whitf., Pal. N. J., vol. 2 (Monog. U. 



S. G. S., vol. 18), p. 104, pi. 12, figs, 1-2. 

 1905. Turbinopsis plicata Johns., Proc. Acad. Nat. Sci. Phil. 



(1905), p. 26. 



Description. "Shell small, and known only from internal 

 casts; spire elevated and erect, composed of but few volutions, 

 probably not more thau three in the shell; widely separated in 

 the casts by the sutures and very rapidly increasing in size; um- 

 bilical opening very large and very distinctly marked, near the 

 base of the columella, by a deep, narrow groove, indicating the 

 presence of a rather strong, tooth-like ridge at the base of the 

 columella; columella concave, giving an elliptical form to the 

 51 PAI, 



