332 RISSOID.E. 



Species of Onoha. 



arctica, Loven. striata, Mont. 



bella, A. Adams. tenella, A. Adams. 



multilineata, Stimp. turriculus, Migh. 

 robusta, Migh. 



Genus barleeia, Clark. 



Operculigerous lobe simple ; foot slightly emarginate 

 posteriorly. 



Operculum testaceous, subannular, under surface with a 

 raised rib, and a long, pointed, testaceous apophysis pro- 

 ceeding from the nucleus. 



Shell turbinately conical, whorls tumid, smooth or 

 transversely striated ; aperture oval, entire, contracted be- 

 hind, rounded in front ; outer lip acute, simple. 



Ex. B. rubra, Adams, pi. 35, fig. 5. 



The tentacles in this genus are short, broad, rounded at 

 the tips, and not setaceous ; the eyes are large, on infla- 

 tions at the outer bases of the tentacles ; the rostrum is 

 simple and not cloven ; the foot is emarginate behind, 

 and the opercular lobe is simple. The operculum is sub- 

 annular, as in Rissoella, and is furnished with a similar 

 appendage proceeding from the nucleus, which latter is 

 nearer the base than the centre. The position of the 

 eyes is similar to that of the other genera of Rissoidce, 

 and the genus seems to differ from Cingula in the circum- 

 stance of the annular operculum, with its long, pointed 

 apophysis ; Rissoina has a similar appendage, but the 

 operculum in that genus is subspiral. 



