50 



applies to my treatment of Haeckel's genus Ascandra, which dates 

 from 1872, since I did not break up the genus into new genera but 

 into two genera much older than the name Ascandra itself; namely 

 Clathrina Gray 1867 and Leucosolenia Bowerbank 1866. Now von 

 Le ndenfeld seems to think that if an old generic name be used with 

 a new diagnosis, it becomes a neAv genus, and that hence the names 

 Clathrina and Leucosolenia as used by me are new genera. This idea 

 is at once shown to be erroneous by § 23 of the German Rules accord- 

 ing to which« a generic name is only valid when a known or sufficiently 

 characterized species (or several species) is referred to it or when a 

 sufficient diagnosis of it is given«. To apply this rule to the present 

 case ; the name Clathrina had as type species the perfectly well known 

 and well characterized "-Grantia clathrus^' of Oscar Schmidt. Hence 

 the name Clathrina was a valid generic name from the first and both 

 Haeckeland von Lend enfeld violated all rules and customs of 

 zoological nomenclature in setting it aside, as they have done, for Aa- 

 cetta and other names. The name Clathrina as revived by me has as 

 type the species clathrus O. S. and when so used it is in no sense a 

 new genus, but is the genus Clathrina Gray, which has been a va- 

 lid genus, according to § 23, for the last 30 years, and remains so as 

 long' as the type species is not altered. Exactly the same argument 

 applies to the genus Leucosolenia^ which had as type the very well- 

 known species botryoides EU. and Sol. and which therefore had equal 

 right to be regarded as a valid genus since 1866. 



The only conclusion to be drawn from the facts is I) that the 

 genera Clathrina and Leucosolenia as used by me are not new genera, 

 2) that therefore my action in dividing amongst these two genera the 

 species, e^ce^t falcata, of Haeckel's genus Ascandra, does not come 

 vinder § 26, and 3) that in consequence the whole of the argument by 

 which von Lendenfeld seeks to establish his genus Homandra 

 falls to the groiind. I hope I have at least shown that the case is by 

 no means so simple as the tone, in which von Lendenfeld discusses 

 it, might lead one to believe. It would be greatly to the advantage of 

 science if those who have been instrumental in drawing up rules for 

 zoological nomenclature, would condescend to pronounce a decision 

 in cases where the interpretation of the rules presents difficulties. To 

 such a decision every one would certainly give way, and thus only, it 

 seems to me, could these discussions upon points of nomenclature 

 come to a termination; discussions which otherwise can be continued 

 for ever without any definite conclusion being reached. 



