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



Genus STYLOPSIS, A. Adams. 



Testa subulata, opaca, laevis, non polita ; anfractibus planulatis, su- 

 turis impressis. Apertura subquadrata, labio recto simplici ; labro 

 in medio recto, antice angulato. 



This genus resembles Eulimella in the simple straight inner 

 lip ; in other respects in surface, texture, and form it is alto- 

 gether different. 



Stylopsis typica, A. Adams. 



S. testa subulata, alba, opaca, non polita, vix rimata ; anfractibus 

 octo, planulatis, suturis impressis, anfractu ultimo subangulato ; 

 apertura subquadrata, columella recta, antice producta, labro 

 margine recto, acuto. 



Hob. Straits of Korea. 



Genus STYLOPTYGMA, A. Adams. 



Testa pupiformis, subpellucida ; anfractibus convexiusculis, transver- 

 sim tenuiter sulcatis. Apertura subquadrata ; labio superne plica 

 obliqua instructo ; labro dilatato. 



Styloptygma Stylina, A. Adams. 

 Proc. Zool. Soc. 1851, p. 224. 



This species is so unlike any other form of Pyramidellida as 

 to warrant its separation. Its nearest approach to any genus 

 hitherto constituted is to Chrysallida of Carpenter, which, how- 

 ever, is longitudinally ribbed or plicate. 



Genus MYONIA, A. Adams. 



Testa ovato-turrita, alba, tenuis ; anfractibus convexiusculis, trans- 

 versim sulcatis, interstitiia caelatis. Apertura oblonga, postice 

 acuminata, antice producta ; labio superne plica obliqua instructo. 



This genus will include most of the species described by me as 

 belonging to Monoptygma in Sowerby's ( Thesaurus/ and should 

 be placed in the family Actaomda. 



Myonia Japonica, A. Adams. 



M. testa turrito- subulata, alba, subpellucida ; anfractibus planius- 

 culis, transversim sulcatis, sulcis distantibus, interstitiis pimctatis ; 

 apertura oblonga, antice subreflexa; labio rectiusculo, superne 

 plica obliqua, vix conspicua, instructo ; labro intus sulcato, mar- 

 gine crenulato. 



Hob. Straits of Korea ; off Niphon. 



Most nearly allied to A. lauta, A. Adams. 



Genus LEUCOTINA, A. Adams. 



Testa ovata, alba, tenuis ; anfractibus convexiusculis, ultimo ventri- 

 coso, transversim sulcatis, interstitiis punctatis. Apertura oblonga, 



