OF CONCHOLOGY. 245 



founds them on the structure of the palettes. The pallettes of 

 JSf. Saulii resemble very closely those of the genus Xylotrya; 

 while those of N. BunJopei are very much like those of an old 

 Teredo, like a large Norvagica for example. 



Annals and Magazines of Natural History. 3d series. London. 



No. 110. February, 1867. 



Description of a new Madeiran Pupa. By R. T. Lowe. 

 Pupa [Alvearella) Wollastoni, Lowe. 



MemarJcs on the History of Dreissena polymorplia. By Dr. 

 Otto A. L. Morch. 



No. 111. March, 1867. 



Description of a new Fresh water Bivalve found in Trinidad. 

 By R. J. Lechmere Guppy. 



Cyclas punctifera, Guppy. 

 No. 112. April, 1867. 



Description of a neiv Land Shell from Trinidad. By R. J. 

 Lechmere Guppy. 



Helicina laynellosa. 



A new sub-genus Perenna is characterized for this species. 

 ^' Operculum thin, sub-oval, concentrically striate ; nucleus sub- 

 central. Shell like Helicina, depressed ; whorls lirate and 

 carinate. Animal like Helicina.'' 



No. 113. May, 1867. 



On the Genus Plectostoma, H. Adams, and on the Animal 

 of Diplommatina, Benson. By Wm. T. Blanford. 



Plectostoma is surmised to be identical, or at most only sub- 

 generically different from Opisthosto7na. 



No. 114. June, 1867. 



Description of some Didian and Burmese Species of As- 

 siminea. By Wm. T. Blanford. 

 The genus Optediceros, Leith, is claimed to be identical with 

 Assiminea. Leith's species are re-characterized also : 

 A. rotunda, Fairbank, MS. A. rubella, Blanford. 



Descrip>tion of a new Species of Rissoafrom Maderia. By 

 J. GwYN Jeffreys. 



R. incta. 



