A, EF. Verrill— Mollusca of the New England Coast. 157 
and to whom the writer is indebted for important assistance in the 
preparation of this paper. 
It is not very probable that this species properly belongs to Pleu- 
rotomella. I have placed it here, for the present, only provisionally. 
Gymnobela Verrill, gen. nov. 
Shell in form and general appearance like e/a. Spire generally 
rather short. Body-whorl swollen. Nucleus with fine cancellated 
sculpture. Subsutural band not strongly marked. Posterior notch 
of lip shallow and usually not very distinct. Operculum absent. 
Gymnobela engonia Verrill. sp. nov. 
Shell somewhat solid, white, more or less translucent, stout-fusi- 
form, with the aperture about equal in length to the spire, which is 
shouldered, decidedly turreted, and tapered regularly to an acute 
apex. 
Whorls five below the nucleus, strongly angularly shouldered at 
about the middle, the portion above the shoulder forming a wide, 
abruptly sloping subsutural band, which is usually slightly concave in 
the middle, but swells a little where it joins the suture ; the whorls 
are flattened below the shoulder and a little narrawed at the suture, 
which is strongly impressed. The sculpture on the subsutural band 
consists of numerous, close, revolving lines, most distinct towards the 
shoulder, and of small, slightly raised, thin riblets, which are most 
distinet close to the suture and strongly excurved in the middle of 
the band, but bend forward strongly to the angle of the shoulder, 
where most of them disappear or blend with the ribs and lines of 
growth a little farther forward. Below the shoulder the surface is 
covered by many, rather thin, closely arranged, revolving cinguli, 
which on the whorls of the spire are separated by interspaces about 
twice their own width, but become muck: closer on the middle of the 
last whorl, gradually becoming coarser and more widely separated 
as they approach the canal, those on the anterior part being also 
thicker and more obtuse. Numerous rather small and slightly ele- 
vated ribs commence at the shoulder and curve obliquely forward 
across the convex part of the whorls, extending to the suture on the 
upper whorls, but mostly fading out at the middle of the last whorl ; 
these ribs are obtusely rounded and wave-like, the interspaces being 
shallow, concave, in breadth about equal to the ribs; on the last 
whorl there are from twenty-five to thirty. On the spire-whorls the 
