Strophomena and Other Fossils 
91 
the shells with the more conspicuous alternation of coarse striae 
with bundles of three or four finer striae were not readily dis- 
tinguishable until the interiors of these shells were better known. 
Moreover Strophomena vetusta was established on a group of 
shells in which the nearly vertical wrinkling along the hinge-area 
was conspicuous, while in the earlier forms, here called Stropho- 
mena vetusta-precursor, this wrinkling is not always so conspicu- 
ous. Hence some specimens of the latter, for instance the one 
represented by Figs. 2 A, B, on plate V of this Bulletin, also 
appear among James’s types of Strophomena neglecta. This 
has made possible the confusion in the interpretation of Stro- 
'phomena neglecta shown by various authors, but a careful re- 
reading of the original description, by one familiar with the 
conditions at Blanchester, and knowing the types, will readily 
verify the conclusion that James never intended to include in 
his Strophomena neglecta the Liberty and Whitewater species, 
Strophomena vetusta, in which the vertical wrinkling along the 
hinge-line is so characteristic. In reading this description by 
James, it should be remembered also that the term Strophomena 
fiUtexta was used by him for the specimens described and figured 
by Meek as that species, and not for the Strophomena filitexta 
of Hall, a species from a much lower horizon. 
The type specimen illustrated by Figs. 1 A and B, on plate 
V of this Bulletin, presents the following characteristics. The 
greatest convexity of the brachial valve is 20 mm. from the beak; 
the thickness of the shell here is 6.8 mm. The valve is distinctly 
flattened posteriorly, especially within 15 mm. from the beak. 
Near the beak, the valve is slightly, but distinctly concave, the 
greatest concavity being 3 mm. from the beak. Hinge-area of 
the pedicel valve with a height of 3.8 mm. at the beak. The 
umbo anterior to the beak is most prominent about 4 mm. from 
the posterior margin of the shell, the general convexity of this 
part of the shell extending for about 13 mm. from this margin. 
Radiating striae of the brachial valve rather fine, every fourth, 
fifth or sixth stria slightly more prominent, about 13 or 14 striae 
occurring in a width of 5 mm. at a point 28 mm. from the beak. 
The striae on the pedicel valve are slightly more numerous and 
finer. 
This specimen is the one referred to by Meek {Paleontology 
of Ohio, vol. I, page 85) when he states that one of the type speci- 
