﻿RHYACIONIA (rETINIA) PURDEYI AND R. LOG^A. 75 



In accordance with Merton Kule No. 48, we should accept this 

 last. This, however, is impossible, as the Jiastianaoi Stephens 

 is neither the true Linnaean species of that name nor hastana 

 Hb., but is ulmana Hb, (see Stephens's List, p. 48).* Hiibner 

 supposed his hastana was the Linnsean hastiana, as shown in his 

 ' Verzeichniss,' p. 379, and also in his ' Systematisch-alpha- 

 betisches Verzeichniss,' page 61, 1822. As he spelled his 

 hastana different from the way that Linnaeus spelled his hastiana, 

 the two names have been retained for these two species. We are 

 obliged therefore, as the Stephens type of Rhijacionia, on 

 page 180, is a species not given originally under Rhyacionia, to 

 reject this and take the restriction on page 178, where turionana 

 Steph. (non Hb.) huoliana Schiff. ; gemmana Hb. (a synonym of 

 the same), and hentleyana Don. {schultziana F.) are the only 

 species given, and as the last was not given by Hiibner, huoliana 

 Schiff. becomes the type of the genus. Lord Walsingham names 

 this same species as the type in the ' Annals and Magazine of 

 Natural History' (7), vol. v. page 124, 1900" (Fernald, 'The 

 Genera of the Tortricidae and their Types,' pp. 9-10). 



Biioliana, Schiff., has been generally accepted as the type of 

 Retinia, Guenee (1845) ; the latter name, however, will have to 

 be merged in Rhyacionia, Hiibn. Meyrick (' Handbook of 

 British Lepidoptera,' p. 471) places huoliana and its allies in 

 Evetria, Hiibn., but previous authors, by removing to other 

 genera four of the five species standing under this generic name 

 in the 'Verzeichniss,' left only tedella, Clerck, and this species 

 therefore became, automatically, the type of Evetria, Hiibn. 

 According to Fernald, Evetria -^- Eucosma, Hiibn., the type of 

 which is circulana, Hiibn., a North American species con- 

 generic with tedella, Clerck. The last-named species, it may be 

 mentioned, is referred by Meyrick to Epihlcma, Hiibn., the type 

 of which was fixed by Stephens a,s foenella, L., but as this also 

 appears to be congeneric with circulana, Hiibn., Epiblema will be 

 a synonym of Eucosma. 



Type fixing by elimination, as exemplified in the cases of 

 Rhyacionia and Evetria referred to above, is a process resorted to 

 when the type of a genus has not been indicated by the original 

 author. As we have seen, this method of ascertaining a type is 

 not so simple as it may look. 



Frequent name changing, whether generic or specific, is of 

 course troublesome, not to say perplexing, but it appears to be 

 inevitable. The modern trend of entomological action has been 

 not only to uphold priority but to enforce it, so that in the 

 present day the "law" is almost universally recognized by syste- 

 matists. Some there are, certainly, who advocate exceptions 

 and restrictions, but if we are ever to have anything approaching 



* ' List of the Specimens of British Animals in the Collection of the 

 British Museum.' Part x. Lepidoptera (1852). — E. S. 



