124 FOSSIL ESTHERLE. 



5. Candona (?) Rogersii, sp. nov. PL V, figs. 20, 21, 22. 



Cypeis, W. B. Rogers. Proceed. Boston Soc. Nat. Hist., 1854, vol. v, 15. 



— J. Leidy. Proc. Acad. Nat. Sci. Phil., June 16, 1857, p. 150. 



— Wheatley. Amer. Jour. Sci. Arts, 2nd ser., 1861, vol. xxxii, p. 42. 



Batrdia, -\ Emmons American Geology, part vi, 1857, pp. 39 and 56. 

 Cypris, J 



Length, -f| inch. Breadth, -fa inch. 



Carapace-valves smooth, oblong, rounded at the extremities, but narrower and obliquely 

 rounded anteriorly ; ventral margin straight, dorsal slightly arched ; hinge-line simple, as 

 in Candona. It is difficult to find a well-preserved and well-exposed specimen on the 

 shales. Eig. 21 is slightly deformed by pressure on the dorsal curves. Fig. 22 is a cast 

 of a narrowish or compressed carapace ; were it broader, it would better represent the 

 common typical form. Fig. 20 is a young individual. The two figured specimens correspond 

 with the two figured by Dr. Emmons in his ' American Geology,' part VI, p. 39, fig. 10. 

 A slight, flat, marginal rim is often apparent, except on the anterior border (fig. 21). 



This is very similar to fig. 14, excepting in size ; but the very great difference in 

 geographical and geological position weighs with me in supposing that this may be spe- 

 cifically distinct from its Palaeozoic and European analogue on one hand, and from its 

 Eocene analogues (C. Forbesii, &c.) on the other. As it is an abundant fossil in the 

 Lower Mesozoic Estherian shales of Virginia and North Carolina, and present in those 

 of Pennsylvania, it is well that it should have a distinct name, and none can be better 

 than one derived from the two eminent brothers who have worked so well on the geology 

 of those regions. 



The chief specimens that I have seen (lent to me by Messrs. Rogers) are from 

 Virginia (Culpepper County, and Prince Edward, near Richmond) and from North 

 Carolina (Deep River). Those from near Richmond arc in black carbonaceous shale ; 

 the valves are numerous on the bed-planes, single, smooth, thin, calcified, and more or less 

 crushed, varying in length from l-24th inch downwards ; the smaller ones appear to be 

 less tapering at the anterior end than the other ; but they are all, I have no doubt, of the 

 same species. Those from Deep River are in a similar black shale, and altogether like 

 those from Richmond above described ; and there are traces of Estheria 1 amongst them. 

 The specimens from Culpepper Co., Virginia, consist of casts and moulds crowded in 

 red shale (on bed-planes), associated with Estheria. 



I have also met with this smooth Candona (?) in the Pennsylvanian shales which were 



1 These fragmentary Estheria certainly appear to be E. ovata, and so far supply the wanting link in 

 my argument respecting the specific identity of the Estherice from the several localities. (See p. 91.) 



