TRUNCATELLID^:. 131 



Risso (1826) in the family of Ellipsostoma ; but he changed the 

 name into that of Truncatella, which must be retained, because 

 Leach's name was not printed. 



Menke was the first who adopted the genus under Risso's 

 name ; he referred it to the family of Turbinea, and added to it 

 several species belonging to other genera. 



Lowe (1831) confirmed the genus which he had in his ma- 

 nuscripts called Erpetrometra, by observation of the animal, 

 and described it more accurately among the genera of Paludi- 

 nidce. To the same family it was referred (1841 and 1843) by 

 D'Orbigny. 



De Cristofori and Jan (1832) founded on the type of Dra- 

 parnaud the genus Choristoma, synonymous with Truncatella. 



In the year 1836 the genus Truncatella was adopted by Can- 

 traine, and (1838) by Deskayes, who declared it nearest allied to 

 Hissoa by the shell and operculum, and intermediate between 

 Rissoa and Pedipes by the character of the animal. 



Anton (1839) regarded Truncatella as a subgenus of Melania, 

 and Swainson (1840) of TurriteUa. 



Dr. Gray acknowledged the genus in his works (1840, 1842, 

 1847 and 1850), and proposed for it the family of TruncatelUda', 

 belonging to the Pectmibranchiata phytophaga iniophthahna. 

 This family is adopted by Lowe (1854), but ascribed to the 

 amphibious Pulmonata Gasteropoda, and by II. and A. Adams 

 (1856), in whose work it is the only family of the suborder of 

 Opisophthalma, and contains the genera Truncatella, Geomelania, 

 Acicida and Tomichia. 



Philippi (1841) adopted the genus Truncatella, the species of 

 which he had before ascribed to Rissoa. In 1844 he referred it 

 to the family of Peristomacea ! 



In 1841 Dr. L. Pfeiffer and Reeve quoted the genus among the 

 family of Cyclostomacea, and likewise Miss A. Catlow, 1845 ; 

 Jay, 1850 ; Dupuy, 1851 ; Philippi, 1853, and Poey, 1854. C. 15. 

 Adams (1851 and 1852) preferred the name of Cychstomidee, 



To the family of Colimacea the genus was referred by G. B. 

 Sowerby(1842) and Thorpe (1844); to Turbinidce by Thompson 

 (1844); to Littorinidce? (1851) by Woodward; and to Pyra- 

 mideUidce by Forbes and Ilanley (1853). 



Finally, Kiister, who published in 1855 a monograph of the 

 genus, with the figures of ten species, did not indicate its 

 systematic place. 



The remaining authors, who have mentioned Mollusca be- 

 longing to this genus, ascribed them to various genera : Pul- 

 teney to Helix ; Montagu to Helix and Turbo ; Draparnaud, 

 Lamarck, Fleming, Scacchi, Michaud and Rossmjissler to Cy- 

 clostoma; Ilartmann to Acmea ; Payraudeau to Paludina; Brown 



