Mr. A. Adams on new Mollusca from Japan. 407 



antice producta; labio superne plica obliqua, saepe celata, in- 



structo. 



This genus is exactly intermediate between Actaon and Myo- 

 nia, and cannot with propriety be ranked with either. It belongs 

 to Actaonida. There are several species, one only of which I 

 shall now describe. 



Leucotina Niphonensis, A. Adams. B V\ \%>7% , \ .Z% . * 



L. testa alba, tenui, oblongo-ovali ; anfractibus 3|, convexiusculis, 

 transversim sulcatis, insterstitiis punctatis ; apertura oblonga, an- 

 tice subproducta ; labio plica obliqua, vix conspicua, instruct ; 

 labro acuto, simplici. 



Hob. Sixteen miles from Mino-Sima, off Niphon ; Straits of 

 Korea ; dredged from 63 fathoms. 



Genus MACROCHEILUS, Phillips. 



In this genus, hitherto considered extinct, the shell is ovate- 

 oblong, with rounded whorls, the last whorl ventricose, and the 

 aperture with no plait on the inner lip, which is thickened. The 

 recent species described below is almost exactly similar in form 

 to M. acutus, De Koninck, but is nearly smooth, being but 

 faintly striated under the lens. 



Macrocheilus JaponicuSj A. Adams. 



M. testa ovato-oblonga, alba, leevi, glabra ; anfractibus sex, rotun- 

 datis, sub lente transversim tenuiter striatis, anfractu ultimo ven- 

 tricoso ; apertura ovali, antice producta ; labio calloso subincras- 

 sato. 



Hab. Straits of Korea ; 63 fathoms. 



Genus AURICULINA, Gray. 



This genus is composed of thin oval shells with simple whorls 

 and without any plait on the inner lip. It is doubtful whether 

 its natural position is not rather in Actceonida than in Pyrami- 

 dellidce. The species already best known have been described 

 as Qdostomia, A. cylindrica, Alder, and A. obliqua, Alder. I 

 now add another and much larger species. 



Auriculina Grayi, A. Adams. 



A. testa ovato-acuta, bulimiformi ; anfractibus quatuor, longitudina- 

 liter substriatis, convexiusculis ; apertura ovali, antice dilatata, 

 postice acuminata ; labio simplici ; labro margine acuto. 



Hab. Straits of Korea ; 63 fathoms. 



Genus ALCYNA, A. Adams. 



Testa acuminato-ovata, imperforata, spira brevi, conica, acuta ; an- 

 fractibus planis, Isevibus. Apertura ovalis ; labio callo incrassato 



