MIOCENE MOLLUSCA AND CRUSTACEA. 75 



Dione Sayana Conrad. 

 Plate xii, fig. 1. 



Cytherea convexa Say; Jour. Acad. Nat. Sci. Phil., 1st ser., vol. 4, p. 149, PI. xn, 



fig. 2. 

 Cytherea Sayana Conrad; Miocene Foss., p. 13, PI. vn, fig. 3, reprint of Say's plate; 



Tuom. and Holmes, P. F. South Carolina, p. 83, PL xxi, fig. 9; Emmons, Geol. 



N. C, p. 294, fig. 1; Heilprin, Proc. Acad. Nat. Sci. Phil., 1887, pp. 401 and 403. 

 Dione Sayana Conrad; Proc. Acad. Nat. Sci. Phil., 1862, p. 575; Meek Check List, 



Miocene Foss., p. 10. 



Below I give the descriptions of this shell by both Dr. Say and Mr. 

 Conrad, as they differ somewhat. Mr. Say's description is: " Shell subcor- 

 date; elevated convex, concentrically wrinkled, inequilateral; posterior 

 tooth and fosset not striated; edge not crenated; umbo rather prominent; 

 lunule dilated, cordate, marked by. a simple line." 



Mr. Conrad's gives the following characters: " Shell subcordate, ventri- 

 cose, rather thin, concentrically wrinkled, inequilateral; umbo prominent; 

 posterior extremity rounded; lunule dilated, cordate, marked by a simple 

 line; anterior cardinal tooth pyramidal, robust. 



It is very evident that the latter description has been written with the 

 former before the author, as much of the same language is used. Conrad's 

 statement that the shell is " rather thin" I have not found to be correct in 

 any of those I have examined ; on the contrary they appear to be generally 

 rather the opposite. I have not seen specimens from any other New Jersey 

 localities than the well-boring of Mr. Woolmans at Atlantic City, and there are 

 only two fragments retaining the hinge portion of the valve, and these have 

 been much waterworn before being reembedded; consequently none of the 

 features can be seen except the general form. I think there is no question 

 as to the identity of the shell, but the specimens are altogether too poor for 

 figuring and for the determination of the species by others, so I have copied 

 Mr. Say's original copperplate figure. 



The specimens are the property of the Academy of Natural Sciences at 

 Philadelphia. 



