306 Mr. A. Adams on new Mollusca from China and Japan. 



striata ; spira planata ; anfractibus rapide crescentibus ; umbilico 

 callo omnino obtecto ; labro producto. 



Hab. Kala-hai; Shan-tung. 



This is a small white semitransparent shell, with the umbilical 

 region entirely covered by a callus, and the outer lip produced. 



2. Ethalia perspicua, A. Adams. 



E. testa perparva, ovato-discoidali, alba, pellucida, striis incrementi 

 conspicuis radiantibus ornata ; spira planata ; anfractibus rapide 

 crescentibus ; basi excavata ; umbilico callo obtecto ; labro producto. 



Hab. Kala-hai; Shan-tung. 



This species differs from E. atomaria in being pellucid, in the 

 umbilical region being impressed, and in the conspicuous ra- 

 diating lines of growth. 



3. Ethalia sobrina, A. Adams. 



E. testa parva, discoidali ; spira planata ; anfractu ultimo ad peri- 

 pheriam obtuse angulato, callo semilunari umbilicum partim te- 

 gente ; labro supra anfractum penultimum dilatato. 



Hab. Tabu-Sima; 25 fathoms. 



The species E. amplectans, Cpr., seems to agree most nearly 

 with this, which has induced me to name it E. sobrina-, it is, 

 however, larger, and does not present the peculiarities in the 

 callus mentioned in the Catalogue of Mazatlan Shells. 



Genus Niso, Risso. 



I may observe here that the only true species of Niso obtained 

 by me in the Sea of Japan are the following : — 



1. Niso interrvpta, Sow. 



Bonellia interrupta, Sow. Conch. Illustr. 

 Hab. Mino-Sima; 63 fathoms. 



2. Niso brunnea, Sow. 



Bonellia brunnea, Sow. Conch. Illustr. 

 Hab. Mino-Sima; 63 fathoms. 



The Bonellia imbricata of Sowerby should form a distinct 

 genus or subgenus, which may be thus characterized : — 



Subgenus Volusia, A. Adams. 



Testa turrita, axi perforata ; anfractibus angulatis, transversim striatis. 

 Apertura subquadrata, antice angulata et producta. 



3. Volusia imbricata, Sow. 



Bonellia imbricata, Sow. Conch. Illustr. 

 Niso imbricata, A. Adams, Proc. Zool. Soc. 



