
A, E. Verrill— Catalogue of Marine Mollusca. 579 
Dacrydium vitreum (Moller) Torell. 
Modiola ? vitrea Moller, 1nd. Moll. Gronl., in Kréyer's Tidsskr., iv, p. 92, 1842. 
Dacrydium vitreum Torell, Spitz. Mollusk fauna, p. 139, pl. 1, figs. 2, a, 6, 1859. 
G. O. Sars, op. cit., p. 28, pl. 3, figs. 2, a, b. 
Verrill, Amer. Journ. Sci., vi, p. 440, 1873; vii, p. 409, 1874. 
PLATE XLIV, FIGURES 8, 8a. 
First taken, on our coast, by the Fish Com., in 1873 and 1874, in 
60 to 142 fathoms, off the coast of Maine and off Cape Cod. Gulf of 
Maine, 160 fathoms; and off Nova Scotia, 102 fathoms, 1877; off 
Cape Cod, 106 and 118 fathoms, 1879. South of Martha’s Vine- 
yard, in 312 to 500 fathoms, stations 891, 892, 894, 947, 994, 997; off 
Chesapeake Bay, station 898, in 300 fathoms. 
North Atlantic, 1450 fathoms,—Valorous Exp. Greenland; Nova 
Zembla; Spitzbergen, 30 ‘to 40 fathoms,—Torell. Finmark and 
Lofoten I. to the coasts of Ireland, England, Spain, and the Azores, 
164 to 2435 fathoms. Mediterranean, 30 to 600 fathoms. Has been 
taken in 30 to 2750 fathoms. 
Idas argenteus Jeffreys. 
Annals and Mag. Nat. Hist., Nov., 1876, p. 428; Proc. Zool. Soc. London, 1879, p. 
570, pl. 45, fig. 3. 
Variety?, lamellosus Verrill. (Perhaps sp. nov.) 
Several living specimens of a species of Jdas were taken by us. 
Our shell resembles Z. argenteus in form and most other characters, 
but there are no radiating lines, such as are attributed to that spe- 
cies; but the surface is covered with well-marked, thin, distant, con- 
centric, raised lamellx, most distinct anteriorly. 
The shell is thin, translucent, covered with a yellowish epidermis ; 
umbos and hinge reddish brown; inner surface iridescent. Some of 
the specimens have several horny, sharp, stiff, beard-like processes 
projecting from the posterior and dorsal surfaces. One of the largest 
specimens is 5°5 long; greatest height, 2°2™™, 
Station 997, in 335 fathoms. 
North Atlantic and Bay of Biscny, 1450 and 994 fathoms,— 
Jeffreys. 
Our shells resemble, in form, the young of Saxicava rugosa. 
TRANS. CoNN. ACAD., VOL. V. 70 JULY, 1882. 
