186 = A. EB. Verrill—Mollusca of the New England Coast. 
Famity SEGUENZID A. 
The beautiful deep-sea shells included in the genus Seguenzia, with 
the closely allied forms (Laszlissa, etc.), present several remarkable 
characters which ought, certainly, to entitle them to rank as a dis- 
tinct family. 
The shell is trochiform, with elegant revolving and transverse 
raised sculpture, and usually translucent, with more or less pearly 
luster, when fresh. .Umbilicus open or closed. Aperture irregular, 
usually with a marked posterior sinus, a short or rudimentary canal, 
or anterior sinus, and sometimes with two anterior sinuses. Oper- 
culum thin, rounded-ovate or ear-shaped, with a subcentral nueleus 
and fine concentric lines. Jaws ovate, with tesselated surface and 
denticulated edge. Odontophore (in Seguenzia) minute, Tawnioglos- 
sate; the central tooth small, with one denticle; the inner laterals 
smaller, with curved unarmed tip; the two outer laterals slender, 
sharp, strongly curved. 
By Jeffreys this group was placed near Solarium (Ptenoglossa) ; 
by Watson in the Zrochide (Rhiphidoglossa). 
It has really no affinity with either of those groups, but belongs to 
the Tenioglossa. It seems more nearly related to Aporrhais and 
allied forms, than to any of our other shallow water groups. 
Seguenzia formosa Jeffreys. 
Jeffreys, Proc. Roy. Soc. London, vol. xxv, pp. 200, 201, 1876 (wood-cuts) ; Ann. 
Mag. Nat. Hist., p. 319, April, 1876. 
Boog Watson, Mollusca Challenger Exp., Part Il], Journ. Linn..Soc., vol. xiv, p. 
587, 1879. 
5 Puate XXXI, riguRES 14, 14a, 14D. 
Several living specimens were dredged by the Albatross in 1883, 
in 1290 to 2033 fathoms. Station 2037, N. lat. 38° 53’, W. long. 69° 
23' 30”, in 1731 fathoms, one young specimen (No. 38,232); station 
2038, N. lat. 38° 30’ 30”, W. long. 69° 08’ 25”, in 2033 fathoms, two 
living specimens (No. 38,078); station 2084, N. lat. 40° 16’ 50”, W. 
long. 67° 05' 15”, in 1290 fathoms, two living specimens (No. 38,247). 
These specimens show some variation in sculpture and in the 
presence or absence of a small umbilical perforation or channel. 
In the typical form of formosa the body-whorl is surrounded by 
three principal carine, which are prominent and rather sharp. One 
of these, around the periphery, is coincident with the posterior angle 
of the aperture, and, therefore, with the suture, which it usually con- 
