PEOCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 365 



Below the sboulder the einguli are numerous and prominent, crossing 

 tlie prominent narrow ribs so as to produce a distinct, but not coarse, 

 cancellation. It most resembles the figures of B. elegans and B. angu- 

 lom of Sars. It is perhaps the original B. decUvis (Loven), but does not 

 agree with Sars's figure. 



Bela tenuicostata M. Sars. 



G. O. Sars. op. cit., p. 237, pi. 17, figs. I a, h; pi. ix, fig. 6 (dentition). 

 Specimens appareutlj^ identical with this species were dredged by me, 

 in moderate depths, at Eastport, Me., in 1864, 1808, and 1870. It was 

 also taken this season at stations 893 and 894, in 365 to 372 fathoms. It 

 is closely related to B. dccussata Couth., but has smaller and more numer- 

 ous ribs, and is, therefore, more finely cancellated. It may be only a 

 variety of B. decussata. The latter is easily distinguished from all our 

 other species by its oval form, rounded, scarcely shouldered whorls, 

 crossed by very numerous small, narrow, flexuous, sigmoid ribs, which 

 are strongly bent backward near the suture, in conformity with the very 

 distinct, rounded sinus of the lip. The whole surface, except close to 

 the deep suture, is covered with numerous rather fine, close, raised, 

 revolving einguli, giving the surface a rather finely and regularly can- 

 cellated structure. 



Bcla Trevelyana (Tnrton) H. & A. Adams. 



This has been recorded by Jeffreys from the Gulf of Saint Lawrence. 

 He formerly united B. decussata with it, but has subsequently (in Mol- 

 lusca of Valorous Expedition) distinguished them. I have myself seen 

 no American shells agreeing clearly with English specimens of B. 

 Trevelyana. The latter resembles B. decussata in form and size, but has 

 the ribs nearly straight and the cancellation coarser than in our shell. 



Bela impressa ? (Beck) Morch, Catal. Moll. Spitzberg, p. 17, 1869. 



Fleurotoma imjircssa Leche, Kongl. Sveuska Vet.-Akad. Handl., Bd. 16, p. 54, 

 pi. 1, fig. IG, 1873 (author's separate copy). 



I refer doubtfully to this species a small but very distinct shell 

 frequently dredged by us, in 10 to 70 fathoms, all along the coast, trom 

 oft' Cape Cod to N^ova Scotia. It was also dredged this season at sta- 

 tions 812 to 815, in 27 fathoms, off Block Island. 



The shell is greenish white, short-oval, with about five whorls, which 

 are distinctly flattened and angularly shouldered near the deep suture. 

 There are on the last whorl about twenty rather broad, flat ribs, which 

 are a little prominent and usually slightly nodose at the shoulder, but 

 they disappear a short distance below. The most characteristic feature 

 is that the surface is marked by rather fine, but regular and distinct, 

 revolving grooves or sulcij which are rather distant, with flat intervals. 

 Of these there are usually about three or four on the penultimate whorl, 

 and about twenty on the last, the greater number being below the mid- 

 dle, on the siiihon, where they become closer; one of the sulci, just below 



