320 TURBONILLID^. 



suture well-impressed ; aperture subquadrangular, columella 

 straight, simple, lip subangular in front. E. typica, A. Adams. 

 Corea. 



Subgenus Menestho, Mdller, 1842. 



Shell turriculated, with spiral strije, or decussated ; aperture 

 oval. M. ALBULA, Fabr. Boreal Seas. 



Pyraviis, of Couthoin^, 1839 (non Schumaclver, 1817), is a 

 synonym. 



Genus ODOSTOMIA, Fleming, 1828. 



Shell small, perforate, oval, conoidal or turriculated ; colu- 

 mella with a feeble, oblique, more or less marked tooth ; aper- 

 ture oval or subrhomboidal, peristome not continuous. Oper- 

 culum horny, lamellar, subimbricated, with a median spiral 

 groove, inner margin indented. 



Animal elongated, the head large and robust, bearing two 

 conical tentacles, with eyes at their bases, foot depressed, trun- 

 cated in front; mentum anteriorly bilobed. 



Very minute, usually smooth shells, having the habit of 

 Rissoae, and, like them, sometimes found in brackish water. 

 The species are numerous, of universal distribution, from low- 

 water to 40 fathoms. F(5%sil, eocene. 0. pltcata, Montagu, 

 Uin'ojie. 



The synon3'ms are Oduntostoma, Turton, 1829; Odontostomia, 

 Jeffreys, 183T. 



The sections will only be used for the division of the Euro- 

 pean species on which they were founded ; those of other 

 localities will be described simply as Odostomije. 



Section Odostomia, sensu stricto. 



Whorls smooth; lip not grooved wi:;hin, coluinellar tooth 

 well marked. 0. plicata, Mont, 



Brachyslomia^ Monts., 1884, is a synon3-m. 



Section Megastomia, Monts., 1884. 



Shell smooth ; aperture large, lip finely grooved within. 0. 

 coNSPicuA, Alder. 



Section Ondina, Folin, 18Y0. 



Shell oval, thin ; whorls smooth or spirallj^ striated, colu- 

 mellar tooth obsolete. 0. obliqua, Alder. 



