250 SCAPHANDER. 



broader ones alternating with finer ones in which the dots are very 

 narrow ; the intervals between the spiral lines are also variable in 

 breadth. None of the specimens appear to have a distinct epider- 

 mic Length of shell to apex of one of the largest specimens 35 

 mill. ; breadth, 25 mill. ; length of aperture, 37 mill. ; greatest 

 l.ivadth of aperture, 18 mill. (F.). 



Off Martha's Vineyard, in 906-1309 fins. ; off Delaware Bay, 1091- 

 1209 fins. ; East from Tobago, in 880 fms. (Albatross). 



S. nobilis VERRILL, Trans. Conn. Acad. Sci. vi, p. 209, pi. 32, f. 1 8, 

 18a, (shell) ; f. 186, c (dentition) ; f. 18rf (gizzard). DALL, Blake 

 Gastr. p. 53 ; Proc. U. S. Nat. Mus. xii, p. 297. 



This species bears some resemblance to S. punctostriatus (Migh.) 

 H. and A. Ad., but is much thinner, with a far more delicate 

 texture. Its form is much shorter and more swollen in the middle, and 

 the spiral lines are less numerous, with wider intervals, and have the 

 punctations larger and not so close together, giving a much smoother 

 appearance to the surface, although the punctate character is quite 

 as evident. The aperture is also much broader, especially in its 

 anterior half, while the body-whorl projects into it much more 

 strongly. The inner lip is much thinner and shows only a slightly 

 thickened fold along the columella-margin. Posteriorly the shell is 

 not at all narrowed, but is evenly rounded, instead of being pinched 

 up as in S. punctostriatu*. The posterior process of the outer lip is 

 more flaring, and extends farther backward beyond the apex. The 

 apex of the shell is nearly plain and smooth, though sometimes 

 slightly indented, and does not have a thickened deposit of enamel 

 extending beyond the edge of the notch, as in the latter. ( F.). 



S. INTERRUPTUS Dall. PI. 32, fig. 26. 



Shell in many respects resembling S. lignarim, and bestdescrilu d 

 by comparison with it. Shell of a livid or gran.-h straw-color, not 

 the yellow or reddish-brown of Hgiim-in*; the tip of the spire is 

 -mailer in proportion and more pointed ; the axis is pervious as in 

 . lint tlic perforation is more cylindrical and d<>'> not become 

 funnel-shaped as the shell enlarges to maturity ; the shell averages 

 more slender; the callus on the body is not reflected so far, and 

 especially on the anterior part of the pillar: the groovesof the sur- 

 face in / without exception are continuous, the punctures 

 being arranged along their channels; in S. infi'rrnjitus the spiral 



