NO. 7 OPINIONS 115 TO 123 25 



Clithoti Montfurt (1810, pp. 326, 327), type by original designation Clithon 



corona (L.)=^ Xcrita corona L. (1758). 

 Neritina 'Lamarck' Rafinesque (1815, Analyse de la Nature, p. 144), ""de 



name. 

 Neritina Lamarck (1816. Encycl. Meth. Vers. IL pi. 455). type designated by 



Children (1822-1823, Gen. Lam., p. in), Neritina puUigcra (L.)." 



Discussion: Neritina Lamarck (with date quoted as 1809) has 

 been and still is usually employed for a widespread group of fresh 

 and brackish water snails of the family Neritidae (Gastropoda 

 Rhipidoglossa). Probably, the European species, Tltcodoxiis fluzn- 

 atilis (L.) is not congeneric with the East Indian N. pulligera, but the 

 position of the East Indian A'^. corona (Clithon) is more dubious. 

 Theodoxiis has come into quite common use, in recent years, for at 

 least the Ein-opean species, although some writers still use Neritina 

 in practically the Lamarckian sense. Clithon has almost never been 

 used in a generic sense, although it is possible that the Conchyliologie 

 Systematique came out in parts, and Clithon is on an earlier page than 

 Tlicodoxns. The fixation of Neritina' as a nomcn conscrvandum would 

 permit the " lumpers " to retain the customary name for the entire 

 group, while the " splitters " could still use Tlicodoxns for the 

 Ein"opean genus. 



Woodward reports : 



Neritina. Regrettable as was the necessary substitution, under the Rules, of 

 Thcodoxus for the once familiar Neritina there is no valid reason beyond senti- 

 ment for reversion to the Lamarckian name. Theodoxus is now so widely used 

 that its abandonment would only create more confusion. In the suggested course, 

 which has its good points, of dividing the genus and using both Theodoxus and 

 Neritina the former by its priority would entail the family name being 

 Theodoxidae. 



Bather reports : 



7. Neritina should stand with genotype A'', pulligera if generically distinct 

 from Theodoxus with genotype A^. fluviatilis. If that be possible I see no objec- 

 tion to retaining the name Neritinidae — but that is another question. » 



Richter (concurred in by Haas and Wenz) reports: 



7. Neritina Lamarck, 1816, mit A^. pulligera (L.) als Typus besteht neben 

 Theodoxus Montfort, 1810, mit Nerita fluviatilis L. als Typus, da (wie es 

 auch der Einsender fiir wahrscheinlich halt: eine zoologische Frage) die Arten 

 pulligera und fluviatilis nicht kongenerisch sind. 



Will man Neritina und Theodoxus als Subgenera in einem Genus vereinigen, 

 so heisst dieses Genus Theodoxus Montfort. 



Da die Spezies corona L., der Genotypus von Clithon Montfort, ebenfalls 

 einem anderen Genus oder mindestens einem anderen Subgenus angehort (wie 

 der eine der Einsender, Baker, in seinen Radula-Untersuchungen, Proc. Acad. 

 Nat. Sci. Phila., vol. 75, 1923, p. 117 s., gezeigt hat) so bleibt auch Clithon 

 Montf. bestehen : als Genus oder als Subgenus Theodoxus (Clithon) Montf. 



