7 



Heliacus, d'Orb., 1841, and Teretropoma, Rochebrune, 1881, 

 are synonyms. Antilles; Pacific 0.; Indian 0. 



Subgenus PSEUDOMALAXIS, Fischer, 1883. 

 Shell discoid al, planorbiform ; whorls and aperture quadran- 

 gular. Operculum as in Torinia restricted. 



Mediterranean ; Madeira. 

 Subgenus GYRISCUS, Tiberi, 1868. 



Shell turbinated, conically turriculated, nmbilicated ; whorls 

 rounded, granulated, spirally sulcatc and ribbed ; aperture sub- 

 circular, the simple margins united by a callous deposit. Oper- 

 culum externally flat and multispiral, furnished internally with 

 a central styliform process (PI. 1, fig. 17). Mediterranean. 



Subgenus EPISCYNIA, Morch, 1875. 



Shell glassy ; periphery with a double series of cilia ; apex 

 simple, direct. Cuba. 



Subgenus CLIMACOPOMA, Fisch., 1883. 



This subgeneric name was proposed by Dr. Fischer (Manuel 

 of Conchyliologie, Fasc., viii, p. 714) upon grounds purely hypo- 

 thetical. When Deshayes found in the Paris Basin a fossil 

 operculum having all the characters of the operculum of the 

 recent Torinia, he suggested that perhaps it belonged to Sola- 

 rium patulum, Lam., but never succeeded in finding it in posi- 

 tion. Dr. Fischer, anticipating the discovery of such a species, 

 with the shell of Solarium and the operculum of Torinia, has 

 proposed for the discoveiy, } r et to be made, the above sub- 

 generic name. 



Genus OMALAXIS, Desh., 1830. 



Shell subdiscoidal, flat or slightly concave above; whorls 

 carinated at the periphery ; peristome not continuous ; umbilicus 

 wide and deep. Operculum multispiral. Bifrontia, Desh., 

 1832, is a synonym. Coast of New England Brazil. Fossil, 



Eocene. 



(E uomphalinse.) 



Genus OPHILETA, Yanuxem, 1842. 



Shell discoidal, planorbiform; whorls numerous, in contact, 

 very convex. Fossil, Paleozoic. 0. levata, Hall. New York. 

 (Struct, and Syst. Conch., PI. 65, fig. 19.) 



