442 A, FE. Verrill—Mollusea of the New England Coast. 
the posterior margin is decidedly oblique and nearly straight, form- 
ing a distinct angle where it joins the dorsal margin. The umbos 
are a little prominent; the beaks are directly incurved, small, and 
situated at about the middle of the dorsal margin. The exterior of 
the shell is rather smooth beneath the epidermis, but covered with 
numerous small, somewhat irregular undulations or ridges, and by 
smaller lines of growth; the radiating lines are very faint or almost 
entirely obsolete over the greater part of the shell, but in fresh speci- 
mens are indicated by the rows of slender epidermal hairs. The epi- 
dermis is light brown, thin, easily removed, and bears numerous radi- 
ating rows of fine slender hairs, which become longer and more 
crowded near the margin. The thin hinge-plate is nearly straight on 
the inside, and bears about three or four teeth on each side of the 
ligament-pit ; three of those on the posterior side being larger and 
more distinct than the rest, while on the anterior side the three lar- 
ger ones are but little prominent and decidedly oblique. The inner 
surface is smooth, and the margin is thin and plain, slightly beveled 
close to the edge. 
Length, 14°"; height, 14™"; thickness, 8°"; length of hinge-mar- 
gin, 8°5"™5 breadth of ligament area, on one valve, 2”. 
Station 2098, in 2,221 fathoms, two living specimens. (No. 35,- 
238.) 
This species resembles, in size and form, the shell which we here 
refer to L. aurita, with which it also agrees in having a plain mar- 
gin, but it differs decidedly in having a much broader ligament area, 
and a much larger cartilage-pit. Its hinge-margin is very much 
thinner, and the teeth fewer, less prominent, and more oblique. Ex- 
ternally the surface is much smoother, the concentric lines smaller, 
and less elevated, while the radial lines are much less distinct. The 
epidermis is thinner and less densely covered with hairs and scale- 
like processes. 
Limopsis affinis Verrill, sp. nov. 
Shell of moderate size, rather swollen, very oblique, with a broad 
and rather short ligamental area, and a short, curved hinge-margin, 
with few teeth. 
The shell is sabovate and very oblique; the dorsal margin is rather 
short and nearly straight, joining the anterior and posterior margins 
with obtusely rounded angles; the anterior margin is rounded and 
projects beyond the anterior angle, and then strongly recedes in a 
broad regular curve, the posterior ventral margin is obtusely rounded 
