A. FE. Verrill—Mollusca of the New England Coast. 209 
Head rounded; hood large, the sides produced backward into 
rounded lobes. Foot long and rather narrow. Gills about twenty- 
four on each side, extending from the posterior end of the foot to 
about its anterior third. 
Length, 17™™; breadth, 8™™; height, 5°5™™; length of shell, 
15°5"™™; breadth, 7™™; length of 1st valve, 3™"; breadth, 6™™; 
length of 3d valve, exposed part, 2"; breadth, 7"; length of pos- 
terior valve, 3°5™™; breadth, 6™™. 
Station 1120, in 194 fathoms, off Martha’s Vineyard, 1882; station 
2069, in 101 fathoms, N. lat. 41° 54’ 50”, W. long. 65° 48’ 35”, 1883. 
This species is readily distinguished from 7. albus by the very 
distinct differentiation of the valves into median and lateral! areas, 
having lines of sculpture running in different directions, and by the 
much coarser granulation of their surfaces. In 7. albus there are no 
distinct lateral areas; the radiating grooves and ridges are absent ; 
and the granulation is so fine and obscure as to be scarcely visible 
without a lens. The spinulation of the marginal membrane is sim- 
ilar in the two species. 
TECTIBRANCHIATA. 
Scaphander nobilis Verrill, sp. nov. 
PLATE XXXII, FIGURES 18, 18a, 18, 18¢, 18d. 
Shell large, swollen, stout, broad-ovate in outline, thin, translu- 
cent, and of an exceedingly delicate texture. The body-whorl is 
very large in proportion to the rest of the shell. The aperture is 
large, broad-ovate in the anterior part, narrowed and curved poste- 
riorly, extending to the apex of the shell, where it terminates in a 
notch, the outer lip extending back considerably beyond the notch. 
The aperture is much encroached upon by the convexity of the body- 
whorl, but about the middle the inner lip is strongly excavated and 
forms a broad and somewhat sinuous curve; the outer lip is very 
broadly and evenly rounded throughout most of its extent; ante- 
riorly the curvature forms the arc of a circle; posteriorly it extends 
back beyond the apex of the shell in the form of an obtuse and 
slightly everted process, with its posterior margin concave, somewhat 
sinuous and spiral, and a little thickened. The surface is smooth and 
polished, somewhat shining, and everywhere covered by spiral lines 
formed by series of oblong dots, which are decidedly sunken below 
the surface, and sepanated by intervals about equal to or less than 
