A. E. Verrill — Catalogue of Marine Mottu&a. 
479 
length of aperture. 6‘5 xm : its breadth. J S ---. One. of the more slen- 
der variety, is 11 '5 m!L long; breadth. 4 "5^' ; length of body-whorl. 
y-lQinm. breadth, 4 XC - ; length of aperture. 5 : its breadth, 2 
This species is found off Martha's Vineyard to Labrador ! It u 
not uncommon in Eastport harbor and the Bay of Fundy. where I 
dredged it in 1864, 186-5, 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 : ■ ff Cape Ann, 38 t< < 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 Vineyai . : .-'a: horns, 1881. 
It appears to occur on the coast of Greenland : Jeffreys records it (a- 
P. pyramidal is) from 5 to 57 fathoms. 
This specie:?, when eroded. i- liable to be confounded with B. co.u- 
ceUata. It differs from the latter in having the wh- rL evenly rounded : 
in its much finer spiral sculpture; and in the shape of the aperture 
and canal. 
Whether it can be identified accurately with any European -pecie- 
is doubtful. Many writers have considered it identical with B. pyra- 
tnidalh (Strom). But the shell figured under that name by Prof. G. 
O. Sars appears to be quite different. 
Mdrch, in 1875, gave a subspecies, pleurotomaria, under I*, pg.-a- 
midalis Strom, from Greenland, and referred ?• it D-fro /■■■>■< Eahl-- 
M oiler, as a synonym. 
Bela 'h<ru*.futa (Couth.) H. and A. Adam-. 
Pleurotoma decusaatu Ooulhouv. Boston -lonm. Xar. Hi-t.. ii. p. 183. pi. 4. 5g. S 
1839 (rum Lam., Macgill. > 
Gould. Rep. on Invert, of Mass.. 1st ed.. p. 280. tig. lv. 1841. 
Mangel* a deeussato Stimpson. shells New Eng., p. 49. Iso'. 
.‘3- 'r • ■ ‘ : -tr V.--- > :.t" - - " - 
Plate XLIII. pigcre 13. 
Shell small, ovate-fusiform, with a tapering spire of mod 
length, scarcely turreted. Whorls -i\ or seven, well-rounded, mod- 
erately convex, constricted above the sutures, round-shouldered, not 
carinated; subsutural band defined only by the curvature of the rib>, 
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 -trough" excurved at 
the shoulder and abruptly incurved at the -lit u re : they fade out 
