Mr. A. Adams on new Mollusca from Japan. 333 



4. Rissoella minima, A. Adams. 



R. testa perparva, umbilicata, lsevi, nitida, subopaca ; anfractibus 3^, 

 convexis, suturis profundis, anfractu ultimo ventricoso, ad peri- 

 pheriam rotundato ; umbilico angusto, rimato ; apertura circulari. 



Hab. Tsu-Sima; 26 fathoms. 



5. Rissoella turgidula, A. Adams. 



R. testa brevi, conoidea, anguste et profunde umbilicata, semiopaca, 

 nitida, alba; anfractibus 3|-, convexis, simplicibus, suturis pro- 

 fundis, anfractu ultimo turgido, ad peripheriam rotundato ; aper- 

 tura ovata ; labio tenui, acuto. 



Hab. Korea Strait ; 46 fathoms. 



6. Rissoella mundula, A. Adams. 



R. testa vix rimata, conoidali, tenui, alba, opaca ; anfractibus con- 

 vexis, simplicibus, suturis profundis, anfractu ultimo amplo ; 

 apertura ovata ; labio tenui, antice subproducto. 



Hab. Tsu-Sima; 26 fathoms. 



7. Rissoella hydrophana, A. Adams. 



jR. testa conoidali, profunde umbilicata, alba, tenui, semipellucida ; 

 anfractibus 3^, convexis, lsevibus, ultimo rotundato, ventricoso ; 

 suturis marginatis ; umbilico patulo, striis radiantibus ornato. 



Hab. Tabu-Sima; 25 fathoms. 



8. Rissoella spiralis, A. Adams. 



R. testa helicoidea, profunde et late umbilicata, tenui, pellucida ; 

 anfractibus 3|, lsevibus, rotundis, suturis profundis, anfractu ultimo 

 ad peritrema vix soluto ; apertura semicirculari ; labio rectius- 

 culo. 



Hab. Sado ; 30 fathoms. 



Genus Syrnola, A. Adams. 



I discovered the type of this pretty little genus (S. gracillima) 

 in 1859, in the Sea of Japan; and since then I have obtained 

 some additional species from deep-water dredgings in the same 

 sea. They are all of small size, and seem to fall very naturally 

 into this group ; they are all banded, and of a vitreous texture, 

 by which, and their subulate or aciculate form, they are readily 

 distinguished from Odostomia, the species of which are white 

 and destitute of coloured markings. Syrnolce, in fact, are small 

 slender Obelisci with a single columellar plait. 



oHjl ! \ !• Syrnola cinctella, A. Adams. 



S. testa gracili, subulata, lsevi, nitida, semipellucida ; anfractibus 9J, 

 planis, linea angusta transversa rufo-fusca ad suturas ornatis ; 

 suturis exaratis ; anfractu ultimo ad peripheriam subangulato, in 



