Strophomena and Other Fossils 
89 
le bord de cedes d’Amerique se retrousse un peu en dessous, tandis que 
c’est le contraire pour cedes d’Angleterre, dont le bord s’abaisse en 
dessous. On trouve a dambouchure de la riviere des Adeghanys pres 
de Pittsborough (Amerique septentrionale) , dans un gres rougeatre, des 
empreintes de coquides qui ont beaucoup de rapports avec cette espece, 
mais qui sont plus aplaties. 
The following is a free translation: 
Shed with lower (brachial) valve convex and with upper, (pedicel) 
valve a little concave, and covered with small radiating striae. Size, 
an inch. Fossil from North America. A figure of a shed belonging to 
this species may be seen in the set of plates accompanying this Dic- 
tionary, on the plate devoted to the illustration of fossils. The sheds 
found at Dudley in England (Strophonella euglypha'?) are closely related 
to this species. They differ chiefiy in that the border of the lower 
valve bends up a little below (when the shed is placed with the brachial 
valve downward), while the contrary is true of the English specimens, 
whose border turns downward. (The last statement is not true, if the 
Dudley shed was Strophonella euglypha.) At the mouth of the Alle- 
gheny River near Pittsburg, in a reddish sandstone, casts of sheds are 
found {Derby a!), which are closely related to this species, but are flatter. 
If the interpretation given in the preceding translation is 
correct, these early writers were impressed more by the pres- 
ence of a prominent deltidium than by the reversal of curvature 
of the shell, unless Defrance had some other shell in mind than 
the common Wenlock species, Strophonella euglypha. The chief 
reason for regarding Strophomena rugosa as a shell in which the 
general curvature of the brachial valve is convex are the figures 
accompanying the text, rather than the description. 
The blunt truth, however, is that when it comes to the identi- 
fication of the species originally described as Strophomena rugosa, 
this is pure guess-work, and the revival of this term, in the absence 
of any type specimens, or fuller subsequent description, or any 
knowledge of the locality from which it was obtained, is not to 
be recommended. 
