188 A. E. Verrill— Mollusca of the New England Coast. 
Odontophore very small and slender; median tooth minute, thin, 
with the tip bent forward and ending in a minute central denticle ; 
inner laterals, with the tip small, curved forward, flat, unarmed, 
almost half as wide as the median; outer laterals long, slender, 
very acute, strongly curved. 
Length of the largest specimen, 5""; breadth, 4°"; breadth of 
aperture, 2™™, . 
At station 2084, two younger specimens were obtained. These, 
while agreeing with the larger specimens in form and sculpture, 
have a narrow but deep umbilical perforation, which is only partially 
concealed by the reflexed columella-margin. One specimen has five, 
the other six spiral carine on the base. The columella-margin is 
thin and shows only a small tooth at its extremity. The nucleus, as 
in the typical form, is small, smooth, turned up obliquely, and some- 
what prominent. The presence of the umbilical perforation seems to 
be due only to immaturity. 
Seguenzia formosa, var. nitida Verrill, nov. 
This shell agrees nearly in form and size with typical S. formosa, 
but is thinner, more translucent, with the spire a little less acute, 
and with more delicate sculpture. It differs chiefly in having more 
numerous and closer spiral lines on the base, the number below the 
median carina of the whorl being ten to twelve, the intervals be- 
tween them diminishing as they approach the umbilical region. 
Our specimens have a narrow, spirally twisted, deep umbilical perfo- 
ration and channel, mostly concealed in a front view by the reflexed 
edge of the columella-lip; the umbilical pore is bordered externally 
by the innermost spiral ridge. The columella is much excurved at 
base, strongly spirally twisted, and projects at the end in a some- 
what prominent, excurved angle, forming a small canal, but has no 
distinct tooth on the inner margin like that seen in the typical S. 
Jormosa, but this may be due to injury; the outer lip is more regu- 
larly convex and has a less developed posterior sinus. The two 
principal carinz on the whorls are elevated and rather prominent, 
with the edge a little thickened, often obtuse and finely spirally 
lined, not interrupted by the transverse riblets, which fade out at a 
littie distance below the crest, except on the sutural carina, which 
they cross. The riblets are rather thinner, more delicate, and more 
numerous than in the typical S. formosa, and are less elevated. 
They are also more strongly curved and decidedly closer together, 
especially those between the two peripheral carine. There is, also, 
