A. E. Verrili— Catalogue of Marine Mollusca. 479 
length of aperture, 6°5""; its breadth, 2°3¥". One, of the more slen- 
der variety, is 11°5™" long; breadth, 4:5"; length of body-whorl, 
7710™; its breadth, 4™™; length of aperture, 5™™; its breadth, 2™. 
This species is found off Martha’s Vineyard to Labrador! It is 
not uncommon in Eastport harbor and the Bay of Fundy, where I 
dredged it in 1864, 1865, 1868, 1870, in 15 to 80 fathoms. By the 
U.S. Fish Com. it has been dredged in Halifax harbor, in 20 to 25 
fathoms, 1877; George’s Bank, 45 fathoms, 1872; Gulf of Maine at 
Cashe’s Ledge, 30 to 40 fathoms, 1874; off Cape Ann, 38 to 40 fath- 
oms, 1874; Casco Bay, 1873; Massachusetts Bay, 31 to 48 fathoms, 
1877, 1879; off Cape Cod, 30 to 122 fathoms, 1879; off Chatham, 
Mass., 16 fathoms, 1881; off Martha’s Vineyard, 255 fathoms, 1881. 
It appears to occur on the coast of Greenland; Jeffreys records it (as 
P. pyramidalis) from 5 to 57 fathoms. 
This species, when eroded, is liable to be confounded with B. ean- 
cellata. It ditfers from the latter in having the whorls evenly rounded; 
in its much finer spiral sculpture; and in the shape of the aperture 
and canal. 
Whether it can be identified accurately with ary European species 
is doubtful. Many writers have considered it identical with B. pyra- 
midalis (Strom). But the shell figured under that name by Prof. G. 
O. Sars appears to be quite different. 
Morch, in 1875, gave a subspecies, plewrotomaria, under P. pyra- 
midalis Strém, from Greenland, and referred to it Defrancia Vahlii 
Moller, as a synonym. 
Bela decussata (Couth.) H. and A. Adams. 
Pleurotoma decussata Couthouy, Boston Journ. Nat. Hist., ii, p. 183, pl. 4, fig. 8, 
1839 (non Lam., nec Macgill.) 
Gould, Rep. on Invert. of Mass., Ist ed., p. 280, fig. 185, 1841. 
Mangelia decussata Stimpson, Shells New Eng., p. 49, 1851. 
Bela decussata, Gould, Rep. on Invert. of Mass., Binney’s ed., p. 354, fig. 623. 1870. 
Ptare XLII. rieure 13. 
Shell small, ovate-fusiform, with a tapering spire of moderate 
length, scarcely turreted. Whorls six or seven, well-rounded, mod- 
erately convex, constricted above the sutures, round-shouldered, not 
carinated; subsutural band defined only by the curvature of the ribs, 
suture well-impressed, not very oblique. Ribs numerous, about 24, 
close, rounded, not very prominent, most so at the shoulder, about 
as broad as their interspaces, sigmoid, usually strongly excurved at 
the shoulder and abruptly imcuryed at the suture; they fade out 
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