576 A. FE. Verrill— Catalogue of Marine Mollusca. 
inner margin are small, regular, and clearly defined, and extend all 
the way round to the dorsal angles; the inner surface of the shell is 
faintly radiated. “The exterior is finely and regularly decussated by 
raised concentric lines and radiating ribs. The epidermis is pale 
horn-color, lamellose, rising into scales and points along the ribs. 
Length, 5™™; beaks to ventral margin, 4™™; thickness, 3°25™™ ; 
length of dorsal margin, 3°6™™, 
Off Martha’s Vineyard, stations 871, 873, 874, 876, and 949, in 85 
to 120 fathoms. About 75 specimens. 
Although resembling some of the other short varieties of A. 
pectunculoides, this seems to be a well-defined form, differing in the 
crenulated margin, and in the character of the hinge-teeth, as well as 
in its tumid form. 
Areca glacialis Gray, 1824. 
Arca glacialis Torell, Spitzbergens Mollusk fauna, p. 153, pl. 2, figs. 7 a, b, 1859. 
G. O. Sars, op. cit., p. 43, pl. 4, figs. 1 a-c. 
Leche, op. cit. [p. 29], pl. 1, fig. 8, 1878. 
This species has been recorded from the Gulf of St. Lawrence, by 
Jeffreys. : 
The New England specimens, formerly referred by me to this 
species, are only large and elongated specimens of A. pectunculoides, 
but they agree very well with Sars’ figures, except that the teeth are 
not quite so numerous. The differences seem to me varietal, rather 
than specific, in so variable a group as this. But as I am uncertain 
whether I have seen a “ true” A, glacialis, I haye let it stand in this 
paper. 
Mr. Dall records it from the Gulf of Mexico, and thinks it distinet 
from A. pectunculoides, but he refers to the latter all the New Eng- 
land shells, that I have sent to him. 
Limopsis minuta (Philippi). 
Pectunculus (Limopsis) minutus Philippi, Enum. Moll. Sicil., p. 63, pl. 5, fig. 3, 1836 
(t. Norman). 
Limopsis minuta G. O, Sars, Moll. Reg. Arct. Norv., p. 44, pl. 3, figs. 5 a-c. 
Jeffreys, Proe. Zool. Soc. London, 1879, p. 585, pl. 46, fig. 9. 
Verrill, Amer. Journ. Sci., xx, p. 392, Nov., 1880; Proc. U. S. Nat. Mus., iii, p. 
402, Jan., 1881. 
Limopsis borealis Jeffreys, Brit. Conch., ii, p. 164; v, p. 174, pl. 100, fig. 3. 
Most of our specimens are rounder and more oblique than the 
figures of Sars and Jeffreys, but the form and degree of obliquity is 
variable. 
