470 A. E, Verrill— Catalogue of Marine Mollusca. 
prove to be only a variety of the latter, as I formerly supposed, but 
it differs much in appearance from the form that I have described, 
above, as the true Bb. exarata. The spire is much longer; the 
whorls are flatter and more regularly turreted, with more regular 
nodules on the shoulder; the ribs are smaller, more regular, and more 
numerous; the spiral cinguli are more numerous, and so nearly equal 
to the ribs as to produce a very regular cancellation: the aperture is 
larger and longer, with a narrower and decidedly longer canal. 
The shell figured by G. O. Sars as B. exarata strongly resembles 
this species in general form and sculpture, and in the uneini, but it 
has a shorter aperture and a wide, open canal, very unlike that of our 
shell. Whether Sars’ shell is identical with the true B. exarata is 
doubtful, for that was described as having a short spire, while his 
shell has a long spire. 
> 
Bela concinnula, var. acuta Verrill, nov. 
Bela mitruia? Verrill, Proc. Nat. Mus., iii, p. 366, 1880. 
PLatre LVI, FiGurReE 10. 
Shell more slender than the preceding, with a longer and more 
acute spire, and narrower aperture. Whorls more flattened, with 
the nodules on the shoulder more prominent and sharper, and the 
carina higher. In other respects it is similar. 
In some examples the ribs are fewer than usual. Sometimes the 
outer lip has a decided ineurvature, just below the angle made by the 
shoulder. 
The uncini (Plate LVII, fig. 10) agree closely with those of 2. eon- 
cinnula, except that they were smaller in the specimen examined,— 
perhaps due to its bemg younger. 
Length of one of the largest examples, 10°"; breadth, 4°2"" ; 
length of body-whorl, 6™ ; its breadth, 3°75""; length of aperture. 
5mm its breadth, 1°6™". 
Casco Bay, 1873; Gulf of Maine, 88 to 118 fathoms, 1873, 1874, 
1877; Massachusetts Bay and Cape Cod Bay, 16 to 20 fathoms.—U. 5, 
Fish Com. 
Specimens intermediate between this variety and B. coneinniula have 
been found, so that it is, doubtless, only a slender form of that species. 
This variety bears considerable resemblance to Bela mitrula Loven, 
as figured by G. O. Sars, and its uncini also agree well with those 
of the latter, so that I formerly thought it might be identical. But 
