PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 373 
ture none, except indistinct lines of growth; surface smooth and shin- 
ing throughout. 
Length of the animal in life about 15" to 20°"; length of Shell, 12.5"; 
breadth, 10". 
etatiéns 870 to 872, south of Martha’s Vineyard, in 86 to 155 fathoms, 
fine sand (16 specimens, living). 
The shell of this species, in form, closely resembles that of the Eu- 
ropean L. perspicua (not of Gould), but the differences in the mantle and 
dentition will clearly separate it. Specimens of both sexes occurred, and 
they had the same form and. color externally. 
The “ Lamellaria perspicua” of Gould was based, in part at least, upon 
Marsenina glabra. A species of Lamellaria occurs at Eastport, Me., 
which may be distinct from the preceding. 
Marsenina prodita (Lovén) Bergh. 
G. O. Sars, Moll. Reg. Arct. Norv., p. 151, pl. 12, ngs. 5 a-c; pl. v, figs. 7 a,b 
(dentition).—Verrill, Trans. Conn. Acad., v, pl. 42, figs. 2, 2a. ° 
This species was taken, living, at Eastport, Me., by Prof. S. I. Smith 
and myself, in 1864 and 1868. It is easily recognized by its compara- 
tively prominent, acute spire, turned to one side, by its obliquely elon- 
gated aperture, and by the margin of the outer lip being slightly inflexed 
near the suture. It has not been previously recorded from the American 
coast, south of Greenland. 
Marsenina glabra Verrill. 
Oxinoé glabra Couthouy, Boston Journ. Nat. Hist., ii, p. 90, pl. 3, fig. 16, 1838. 
Lamellaria perspicua (pars) Gould, Binney’s ed., p. 337, fig. 607 (?). 
Marsenina micromphala Bergli.—G. O. Sars, op. cit., p. 151, pl. 21, figs. 10 a-d.— 
Verrill, Trans. Conn. Acad., v, pl. 42, figs. 1, 1a. 
This species is not uncommon at Eastport, Me., where I collected it in 
1859, 1861, 1863, 1864, 1868, 1870, and 1872. It was dredged last year 
by our party, on the “Speedwell”, off Cape Cod, in 34 fathoms. It has a 
much smaller and less prominent spire than the preceding, and a more 
regularly oblong-oval aperture. The shell is smooth, white, thin, and 
delicate in both species, but more translucent in the present one. 
There can be no doubt, from the description and figure, that the O.rinoe 
glabra of Couthouy was a Marsenina indistinguishable from this species, 
which is the commonest of the group on our coast. The JM. microm- 
phala, well described and figured by Sars, appears to agree perfectly 
with our form, both in the animal and shell. 
Gould appears to have confounded two or more species fader his LD. 
perspicua. His figure (158) in the first edition does not represent this 
species ; the figure 607 of Binney’s edition is different, and may be this 
shell. As a genuine Lamellaria, having its shell entirely inclosed in the 
mantle, also occurs on our coast, not rarely at Eastport, Me., it is not 
improbable that Gould may have had its shell among those examined 
by him. Its identity with L. perspicua of Europe is very doubtful, 
however. 
