﻿39G PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 

 LAMELLIBRANCHIATA. 



Poromya granulata (Nyst) Forbes & Htiulcy. 



G. O. Sars, op. cit., p. 90, figs. G a, h. — Yerrill, Traus. Conn. Acatl., v, pi. 44, 

 tigs. i5, 4. 



Several adult living- examples of this shell were dredged in 1872 by Dr. 

 A. S. Packard and 31r. C. Cooke, on the Coast Snrvej- steamer -'Baelie", 

 in the Gulf of Maine, iu 150 fathoms, miid. This season it was taken at 

 station 805, in 05 fathoms. It has not previously been recor<led as 

 American. 



In form and size it somewhat resembles Thracia mi/op.ns, but is easily 

 distinguished by the small granules scattered over the exterior, and by 

 the peculiar hinge, very different from that of Thracia. The right valve 

 has a prominent, recurved, cardinal tooth. On the European coast it 

 ranges fi'om the Lofoden Islands to the Mediterranean, iu deep water. 



Poromya rotundata Jeifreys. 



Annals and Mag. Nat. Hist., Dec, 187G, p. 494 (Valorons Expedition, Mol- 

 Insea). 



Shell rounded, thin, translucent, pearly within. External surface 

 closely covered with small, rounded, obtuse granules, arranged mostly 

 in close quincunx, and distinctly forming radiating lines, but in some 

 p;irts appearing to be also iu concentric lines. The narrow intervals 

 between these lines of granules show the iridescent surface of the shell. 

 These granules give a shagreen-like appearance to the shell. The gran- 

 ules show tlirough on the inside, giving a finely tessellated appearance. 

 The shell is but little longer than broad, convex; ventral and anterior 

 edges evenly rounded ; posterior dorsal edge a little sloping, and form- 

 ing an obtusely rounded angle where it meets the curvature of the pos- 

 terior end. Hinge of right valve with a prominent cobical tooth, fitting 

 into a corresponding pit in the left valve. 



South of Martha's Vineyard, stations 805 and 871, 05 to 115 fathoms, 

 living ; North Atlantic, 1,450 fathoms (Jeffreys). 



Lyonsiella abyssicola M. Sars ; Friele. 



I'ccchiiilia (ibi/s.'iicola G. O. Sars, Remarkable Forms Anim. Life, i, p. 25, pi. 3, 

 ligs.'>l-4:{; Moll. Reg. Aret. Norv., p. lOS, i)l. 20, ligs. 5 a-d. 



A few good living specimens of this interesting addition to the Ameri- 

 can fauna were dredged by our party this season, south of Martha's 

 Vineyard and Newport, in 192 to 500 fathoms, fine, compact sand and 

 mud (stations 801), 880, 891, 892, 891). 



Lyonsiella gemma Venill, sp. nov. 



Shell small, iridescent, white, with raised radii, broad oval, widest 

 and broadly rounded anteriorly, expanded and broadly rounded ven- 

 trally, posterior end short, narrowed, and tapered to an obtuse jjoint. 

 The beak is subcentral, but a little nearer the anterior end, prominent, 

 intiated, strongly curved inward and forward. Dorsal margin abruptly 

 incurved ojiposite the beaks and decidedly expanded and excurved in 



