A. E. Verrili— Mollusca of the New England Coast. 439 
The anterior margin is nearly straight, the posterior dorsal margin 
is slightly convex ; the two form an acute angle, while the ventral 
margin is broadly rounded, or sometimes subtruncate in the middle, 
so that the anterior and posterior angles are obtusely rounded, the 
posterior end being a little more prominent. The shell is somewhat 
swollen in the larger specimen. The beaks are small and curve 
directly inward. The hinge-margin is stout, with a rather large 
cartilage-pit. The anterior row includes about eight elevated, acute 
teeth, nearly in a straight row; the posterior row is a little curved, 
and includes about ten similar teeth. The interior is pearly, with 
strongly marked muscular sears. The margin is plain. The epi- 
dermis is firm, smooth, closely adherent, and light greenish yellow 
in color. 
Length of the largest specimens, 1°5™™; height,.5™"; breadth, 
3mm, Younger specimens are not quite so high in proportion to 
their length. 
Station 2,194, in 1,140 fathoms, one valve; station 2,228, in 1,582 
fathoms, one live specimen; and station 2,229, in 1,423 fathoms, 
N. lat. 37° 38’ 40”, W. long. 73° 16’ 30”, six live specimens. 
This species is remarkable for its triangular form and the acute 
angle formed by its dorsal margins, as well as for its smooth and 
lustrous exterior. In all these characters it differs widely from all 
our other species. 
Area profundicola Verrill and Smith, sp. nov. 
PLATE XLIV, FIGURES 23, 23a. 
Shell rather small, elongated, angular and oblique, very inequi- 
lateral, with the posterior end elongated and expanded; the anterior 
end short and oblique, angulated above; the ventral margin oblique 
and incurved in front of the middle. 
The shell is covered with a rather coarse, dark brown epidermis, 
rising into elongated and conspicuous scales and lamellae, which 
become longer and more conspicuous posteriorly, where they form a 
fringe beyond the margin. Beneath the epidermis the sculpture. 
consists of small, wavy, concentric ridges, parallel with the lines of 
growth, and of rather fine, regular, radiating grooves, separated by 
rather wider, rounded interspaces, which are often a little nodulous 
in crossing the concentric ridges. The beaks are prominent, angu- 
lar, curved inward and a little forward, and somewhat flattened in 
the middle. <A flattened or somewhat indented area extends from the 
beaks to the margin. The dorsal margin is straight and is about 
TRANS. Conn. Acad, Vou. VI. 55 May, 1885, 
