402 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



atious of A. glaeialis. The shortest and most rounded forms that we have 

 taken were dredged south of Martha's Vineyard and south of Xewport, 

 in 85 to 225 fathoms, this season. 



Limopsis ciistata (?) Jeffreys. 



Anu. and Mag. Nat. Hist., 1876, p. 434; Proc. Zool. Soc. Loudou, 1879, p. 585, 

 pi. 40, fig. 8. 



A few dead specimens, referred doubtfully to this species, occurred at 

 stations 805 to 867 and at 870 and 871, in 65 to 155 fathoms. 



Limopsis minuta (Philippi). 



G. O. Sars, Moll. Reg. Arct. Norv., p. 44, pi. 3, figs. 5 a-c. 



Limopsis boreal is Jeffreys, Brit. Conch., ii, p. 164; v, p. 174, pi. 100, fig. 3. 



This shell was taken in abundance, living, at stations 893, 891 and 895, 

 in 238 to 372 fathoms ; in smaller numbers at 891 and 892, in 487 to 500 

 fathoms ; and sparingly at several other localities in 115 to 252 fathoms. 



Modiola polita Venill & Smith. 



Amer. Journ. Sei., xx, p. 400, for Nov., 1880 (published Oct. 25). 



Two living specimens were taken at station 895, in 238 fathoms. 



Avicula hirundo (?) L., var. nitida, uob. 



The shell is very inequivalve, the right shell being smaller and flatter, 

 and much bent inward near its ventral edge. The form is very oblique, 

 with the anterior ear small and short, in the left valve, and separated from 

 the body of the shell by a slight incurvature of the edge, from which a 

 depression runs to the beak ; right valve with a shallow byssal notch. 

 Posterior ala short, triangular, with a rounded incurvature of the pos- 

 terior edge of the shell, separating it from the body of the shell, which 

 is x)roduced and rounded at the end. Surface nearly smooth, glossy, 

 and somewhat iridescent, with regular but inconspicuous lines of growth, 

 which on the anterior ears rise uj) into thin, wavy lamell*. 



Color translucent, pale yellowish, usually with a brown streak radi- 

 ating from the beak to the outer edge. 



Length, beak to outej- edge, 13"""; length of hinge-line, 11"""; beak to 

 end of ijosterior ala, 8""". 



This shell was found in considerable numbers adhering to hydroids, 

 in 05 to 192 fathoms, south of Martha's Vineyard (stations 865 to 867, 

 and 869 to 873). In form it resembles the young Avicula hirundo of 

 Florida and the West Indies. It is, however, much smoother and more 

 lustrous than any specimens of that species which I have hitherto seen, 

 and may well prove to be a distinct species, for which I would, in that 

 case, propose the name nitida. 



Limaea subovata (Jeffreys). 



Lima suhovata Jeffreys, Annals and Mag. Nat. Hist., Nov., 1876, p. 427. 



Shell small, Avhite, ovate, nearly e«iuilateral, with the valves convex, 

 much swollen in the middle; beaks prominent, incurved; hinge-line 

 straight, shorter than the shell ; ligament- pit narrow, elongated, lunate. 



