92 
Aug. F. Foerste 
mens of Strophomena neglecta was much more elongated on the 
hinge-line, and evidently had more acutely angular lateral extrem- 
ities. He states, moreover, that all the type specimens have 
nearly the same sized striae, corroborating the view expressed 
above, that James did not intend to include shells of the type of 
Strophomena vetusta in his original description of Strophomena 
neglecta. 
The muscular area of the pedicel valve of this species is large, 
forming about two-fifths of the width of the shell at the hinge- 
line. One of the chief diagnostic characteristics of the species 
is the presence of a series of radiate markings crossing the muscu- 
lar area, resulting in a flabellate scar. The muscular area is 
traversed by a median ridge, which widens along the posterior 
half and bears the adductor scars. The outline of the muscular 
area is nearly circular, or sometimes more narrow and elliptical. 
The exterior edge of the border usually is abruptly elevated above 
the general surface of the interior of the valve, but the impressed 
muscular area rises rather gradually toward the anterior part 
of this border. Occasionally, the border rises only slightly above 
the general surface of the interior. In this case, the general 
surface of the interior of the shell is covered by numerous, minute 
papillae, arranged more or less parallel to the radiating striae 
seen on the exterior of the shell; and the shell is only slightly 
thickened toward the border. In specimens having a prominent 
border limiting the muscular area, the minute papillae are seen 
chiefly toward the margin of the shell, the parts surrounding the 
muscular area usually being covered with stronger, more or less 
radiating markings, which occasionally are broken up into irreg- 
ular series of elongated papillae, similar to those identified as 
ovarian markings. The thickening of the shell toward the anterior 
and lateral margins of the interior usually is not conspicuous. 
The interior of the brachial valve is marked by numerous minute 
papillae, except toward the muscular region, where they become 
larger. There is a tendency toward the arrangement of these 
papillae in more or less radiating rows. The adductor scars 
are distinctly limited posteriorly, but anteriorly their outline is 
rather vague. A triangular thickened area extends from the 
cardinal process forward, and then is extended across the adduc- 
tor area as a low median elevation, disappearing near the ante- 
rior edge of the adductor area. The vascular ridges and sinuses, 
