WATSON : NOTES ON NOMENCLATURE OF HYGROMIA, HELICEI.LA, ETC. 279 



as a section of the subgenus of wliich H. hispida is the type — it is a 

 distinct subgenus ; therefore the name Perforatella must clearly not 

 be used in the place of Trichia Hartmann. 

 Helicella Ferussac 



Messrs. Gude and Woodward maintain that Pilsl^ry and others 

 are wrong in applying the name Helicella Fer. (182 1) to the well- 

 known Helicid genus which Held called Xerophila in 1837, and they 

 state that Ferussac's name must he applied instead to the equally 

 well-known Zonitid genus of which the type species is H. cellaria 

 Miill. It is evident that this transference of the name Helicella from 

 one genus to another will cause endless confusion, but Gude and Wood- 

 ward seek to justify the proposed change on the grounds, apparently, 

 that in 1847 Gray "fixed" H. cellaria Miill. as the type of Helicella 

 Per., and that, in any case, " it is quite obvious " that the name 

 Helicella Fer., "can only be applied" to certain members of the 

 second of the four groups into which Ferussac divided his subgenus 

 and which he named " Les Aplostomes," because they say that he 

 indicated that this group " contained his typical Helicellas." Yet 

 they give no justification whatever for this last statement beyond the 

 fact that Ferussac regarded this second section of his subgenus as 

 the most nearly equivalent to the group which he apparently believed 

 had been named Helicella by Lamarck. 



In May, 1847, about six months before Gray's paper was published 

 or even read, Herrmannsen^ designated H. ericetonun Miill. { = H. 

 itala Lin.) as the type of Helicella as restricted by Hartmann in his 

 " Erd- u. Siissw.-Gasteropoden der Schweiz" (1840-44). In this work 

 Hartmann states with truth (on p. 143) that Ferussac's subgenus 

 Helicella comprised a heterogeneous mass of species, and he there- 

 fore restricts the name to the group containing H. cespitmn, striata, 

 costi4lata, apicina, ericetorum, obvia, etc. ; de Charpentier^ had already 

 in 1837 excluded from Helicella the species now placed in the 

 Zonitidae and Endodontidffi. Gray,'^ on the other hand, merely gives 

 H. cellaria as the type of Ferussac's ''■Helicella {liyalina)" — the 

 equivalent of Helicella Beck — in the same way as a few lines lower 

 down he gives H. algira as the type of Ferussac's " Helicella 

 (yerlicelli)" another of the groups into which the French author 



1 " Indicis Generum Malacozoorum Primordia," vol i, p. 507. Doubts have been expressed 

 as to the validity of Herriiiannsen's designations of type species, as it has been said that he did 

 not profess to select types. But these doubts are not supported by a careful study of Herrmann- 

 sen's Latin Introduction to his work, which seems to contain nothing to imply that when he states 

 in his book that certain species are the types of certain genera he does not mean what he says. 

 And even if there were good evidence that Herrniannsen did not himself select the types that he 

 gives, but merely published the selections that had been made by others, this would not effect the 

 validity of his designations. The suggestion that H. ericetorum was not the only species which 

 Herrniannsen, in his Index, designated as the type of Helicella, is also incorrect. 



2 Neue Denkschr. d. Allg. Schweiz. Gesells. f. d. ges, Naturwiss. , vol. i. 



3 Proc. Zool. Soc, 1847, p. 174. 



