PKOCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 373 



ture uoue, except indistiuct lines of growth ; surface smooth and shin- 

 ing throughout. 



Length of the animal in life about 15""" to liO"""^ length of shell, 12.5"""; 

 breadth, 10'""'. 



Stations 870 to 872, south of Martha's Vineyard, in 8G to 155 fathoms, 

 fine sand (IG specimens, living). 



The shell of this species, in form, closely reseiid^les that of the Eu- 

 ropean L. perspiena (not of Gould), but the differences in the mantle and 

 dentition will clearly separate it. Specimens of both sexes occui-red, 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 LameUaria occurs at Eastport, Me., 

 which may be distinct from the preceding. 



Marseuiiia prodita (Loven) Bergh. 



G. O. Sars, Moll. Reg. Arct. Now., ]). 151, pi. 12, ligs. 5 a-c; pi. v, figs. 1 a,h 

 (dentitiou). — Verrill, Trans. Coim. Acad., v, pi. 42, figs. 2, 2 a. 



This species was taken, living, at Eastport, Me., by Prof. S. I. Smith 

 and myself, in 18G4 and 18G8. It is easily recognized by its compara- 

 tively prominent, acjute spire, turned to one side, by its obliquely elon- 

 gated ai)erture, and by the margin of the outer lip being slightly iuflexed 

 near the suture. It has not been previously recorded from the American 

 coast, south of Greenland. 



Marsenina glabra Verrill. 



Oxinoii (jlahra Couthoiiy, Boston Joiirn. Nat. Hist., ii, p. 90, pi. .3, fig. 16, 1838. 

 LameUaria persincitn (pars) Gould, Binney's ed., p. 3:37, fig. 607 (?). 

 Marsenina micromphala Bergli. — G. O. Sars, op. cit., p. 151, i)l. 21, figs. 10 a-d. — 

 Verrill, Trans. Conu. Acad., v, pi. 42, tigs. 1, la. 



This species is not uncommon at Eastport, Me., where I collected it in 

 1859, 1861, 18G3, 18G4, 1868, 1870, and 1872. It was dredged last year 

 by our party, on the " Speedwell", off Cape Cod, in 31 fathoms. It has a 

 much smaller and less prominent spire than the i)receding, 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 Oxino'e 

 fjlahra of Couthouy was a Marsenina indistinguishable from this species, 

 which is the commonest of the group on our coast. The 21. microm- 

 phala, well described and figured by Sars, appears to agree perfectly 

 with our form, both in the animal and shell. 



Gould apiiears to have confounded two or more species under his L. 

 pempicua. 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 LameUaria, 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. 



