442 A. E. Verrill — Molhisca of the Nev) Enqland Coast. 



the posterior margin is decidedly oblique and nearly straight, form- 

 ing a distinct angle where it joins the dorsal margin. The umbos 

 ai'e 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 ei)idermis, 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 

 lio-ament-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, 1 4""" ; thickness, 8'"™ ; length of hinge-mar- 

 o-in, 8'5"'™ ; 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 whicli we here 

 refer to Ij. aurita, with which it also agrees in having a plain mar- 

 gin, but it diifers 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. 



Liimopsis affiniS Verrill, sp. nov. 



Shell of moderate size, rather swollen, very oblique, with a broad 

 and rather short liganicntal area, and a short, curved hinge-margin, 

 with few teeth. 



The shell is subovate 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 

 proiects beyond the anterior angle, and then strongly recedes in a 

 broad regular curve, the posterior ventral margin is obtusely rounded 



