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Aug. F. Foerste 
tening of the brachial valve extending for more than half the 
length of the shell from the beak were noticed at Clifton, and 
near the home of W. D. Helton, on Beech Creek, 3 miles north- 
west of Waynesboro. Others, with the flattening extending only 
as far as the middle, were seen at Riverside, and along Leipers 
Creek in Maury county, north of Fly’s store. A specimen from 
the last locality is illustrated by Figs. 4 A, B, on plate VII and 
Figs. 14: A, B, on plate IX of this Bulletin. 
A pedicel valve from Iron Ridge, Wisconsin, forming No. 8191 
of the University of Minnesota collection, is illustrated by Fig. 
8 (magnified) on plate VII of this Bulletin. The muscular area 
resembles that of Fig. 7 A on the same plate. The interior of 
the body cavity is marked by minute granules arranged in 
radiate lines, about 35 in a width of 5 mm. These granules are 
characteristic of the species. The valve is very flat, and is very 
moderately curved at the anterior end. 
Excepting in the outline of the shell, the last specimen closely 
resembles the specimen of Strophoniena neglecta from Oregonia, 
Ohio, illustrated by Fig. 3 A, on plate V. The latter specimen 
presents the same flabellate scar, scarcely rising above the body 
cavity at the border, and also the numerous minute granules 
arranged more or less in radiating series. Other specimens of 
Strophomena neglecta occur which resemble the larger valve of 
Strophomena planodorsata illustrated by Schuchert from Wilming- 
ton, Illinois (illustrated also by Fig. 6, on plate VII, of this Bulle- 
tin). In fact, the interiors of Strophomena neglecta vary consid- 
erably, but all agree in having flabellate muscular areas, and 
numerous small granules more or less arranged in radiating lines, 
but the size of these granules varies considerably. 
The prominence of the border surrounding the muscular area 
of the pedicel valve is not of diagnostic value. This feature 
varies considerably in different individuals of the same species. 
Typical specimens of Strophomena planodorsata from the Fern- 
vale at Wilmington, Illinois, often have prominent borders, 
while in a suite of specimens from Sterling, Illinois, regarded as 
Strophomena neglecta, this border varies from fairly prominent to 
as low as in the specimen here figured from Iron Ridge. In 
these specimens from Sterling, the shell usually is about 27 mm. 
long, 40 mm. wide at the hinge-line, and only 35 mm. wide 
about 9 mm. in front of hinge-area. There are 11 or 12 sub- 
