374 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



Marsenina ampla Verrill, sp. nov. 



Trans. Conn. Acad., v, pi. 42, figs. 3, 3a. 



Shell broad-oval, white, nearly opaque, fragile, with conspicuous lines 

 of growth, but otherwise smooth ; whorls scarcely two ; last whorl very 

 large, constituting nearly the entire shell, and nearly concealing the first 

 whorl, which appears only as a minute incurved nucleus, situated in an 

 apical depression. Ajjerture broad, oblong-oval, showing the interior 

 of the spire to the apex. Outer lip thin, distinctly expanded and slightly 

 shouldered near the suture, somewhat straight along the right and left 

 sides, regularl}^ rounded in front, slightly excurved where it joins the 

 inner lip, which consists of a narrow and thin coating, conformable to 

 the columella surface, but with a distinct, narrow groove, and with the 

 edge slightly raised as a narrow lamina in the umbilical region. The 

 columella-edge is sigmoid and very much incurved in the umbilical 

 region. 



Length, 11""" ; breadth, 8™™ ; depth of last whorl, 5""". 



Eastport, Me. Dredged in 1868, by the writer. 



Velutella cryptospira (Middenrt.). 



G. O. Sars, Moll. Reg. Arct. Norv., p. 149, pi. 21, figs 9 «-c. 



A good living example of this shell was taken by us in 1877, off Hali- 

 fax, Nova Scotia, in 57 fathoms (station 82). 



The shell is very thin, translucent, yellowish horn-color, flexible, and 

 but slightly calcified, with no sculpture except fine lines of growth. 

 The spire is small, incurved, and depressed, so that the apical whorl is 

 not visible in a front view. The aperture is elongated. The outer lip 

 expands rather abruptly posteriorly, and is prolonged anteriorly. 



Length, 8"""; breadth, 5"""^ length of aperture, 6.5""". 



Trichotropis conica Moller. 



Kioyer's Tidss., iv, p. 85, 1842.— G. O. Sars, op. cit., p. 163, pi. 13, fig. 3. 



A single dead, but large and characteristic, specimen of this very dis- 

 tinct species was taken in the Gulf of Maine, off Cape Sable, Nova Scotia, 

 in 75 fathoms, by the United States Fish Commission party, on the 

 " Speedwell ", in 1877. It is easily recognized by its conical spire and its 

 flattened base, covered with revolving grooves and ridges. The revolv- 

 ing ribs on the spire are stronger than those on the base, and unequal. 



Rissoa (Cingula) harpa Verrill, sp. nov. 



Shell small, white, translucent, acute-conical, with five very convex, 

 rounded whorls and deeply impressed sutures ; body-whorl large ; api- 

 cal whorl very small, smooth, regular. Sculpture very regular, well- 

 raised, roundeil, transverse ribs, about twenty-six on the last whorl, sep- 

 arated by spaces rather wider than the ribs ; and fine, close, microscopic 

 spiral lines, which cover the interspaces. Aperture nearly circular, 

 slightly effuse in front. Outer lip thin, regularly rounded; inner lip 

 refl(5xed in the umbilical region, and continued on the body- whorl only 



