A. JE. Verrill — Mollusca of the New England Coast. 209 



Head rounded ; hood lai-ge, 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, IV"'"; breadth, 8"""; height, 5-6'""' ; length of shell, 

 15-5'"'"; breadth, V'"™; length of 1st yalve, 3'""'; breadth, 6°"^^; 

 length of 3d valve, exposed part, 2""" ; breadth, V'"'" ; length of pos- 

 terior valve, 3-5™'"; breadth, 6°"". 



Station 1120, in 194 fathoms, oiF 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 ai'eas, 

 having lines of sculpture running in different directions, and by the 

 much coarser granulation of their surfaces. In T. 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 spiiiulation of the marginal membrane is sim- 

 ilar in the two species. 



TECTIBRANCHIATA. 

 Scaphander nobilis Yerriii, sp. nov. 



Plate XXXIT, figures 18, 18a, 18&, 18c, \M. ■ 



Shell large, swollen, stout, broad-ovate in outline, thin, translu- 

 cent, and of an exceedingly delicate texture. The body-wiiorl 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 separated by intervals about equal to or less than 



