A. E. Verrill—Mollusea of the New England Coust. 147 
subsutural band. The animal is destitute of an operculum, and, in 
all the species hitherto examined, is without eyes. The dentition 
consists of rather strong uncini, usually with a barbed tip and broad 
base. 
This genus, therefore, resembles very closely the shallow-water 
genus, Defrancia, to which many of the described species have been 
hitherto referred ; but in Defrancéa the outer lip is thickened, or has 
a distinct varix, and there is usually a deposit of callus on the body- 
whorl, especially posteriorly, opposite the sinus, while the animal, in 
the typical species at least, has well developed eyes. 
Pleurotomella Bairdii Verrill and Smith, sp. nov. 
PLATE XXXI, FIGURE 1. 
Shell large, rather stout, fusiform, with an elevated, acute, turreted 
spire and eight or nine obtusely shouldered, angular whorls. The 
last whorl is large and somewhat inflated, with a broad, flattened or 
slightly concave, sloping subsutural band, which is covered with dis- 
tinct, strongly receding lines of growth and with more or less evident, 
raised, spiral cinguli and grooves. Below the subsutural band the 
whorls are obtusely angulated, but without a distinct carina. Com- 
mencing at the shoulder and extending a short distance below it are 
numerous oblique, not very, elevated, longitudinal ribs, which fade 
out before reaching the middle of the whorls. The whole surface of 
the whorls, including the ribs, is covered with conspicuous, raised, 
spiral cinguli, between which there are two or three smaller ones, sepa- 
rated by deep concave grooves of about the same breadth ; the whole 
surface is covered by distinct, raised lines of growth. ‘The aperture 
is oblong-ovate, rather large ; the columella is nearly straight, some- 
what prolonged, its inner edge forming a slight sigmoid curve; the 
canal is short, broad, narrowed at the tip and not recurved; the outer 
lip is sharp and thin; the posterior sinus is broad and rather deep, 
with regularly rounded margins, corresponding to the lines on the 
sub-sutural band; below the shoulder the lip projects considerably 
forward and then is somewhat flattened and recedes gradually to the 
base of the short and broad canal. The nuclear whorls are very 
small and generally eroded so far as to appear smooth. 
The shell is white or grayish white, without any distinct epidermis ; 
aperture clear white. The animal is destitute of operculum and eyes. 
In the number of specimens examined there is considerable varia- 
tion in the ratio of length and breadth, depending largely on the 
TRANS. Conn. Acap., Vou. VI. 19 APRIL 12, 1884. 
