734 



ME. E. m'lACHLAN ON SPECIES 



and 1 propose to pass over Ins present remarks without comment, 

 so far as regards them. But in a few other instances the results 

 arrived at appear to be open to question, and they bear also the 

 inconvenience of upsetting widely and generally adopted nomen- 

 clature, which should be avoided so far as is consistent with the 

 due recognition of the rule of priority. In these few instances 

 I do not feel justified in abandoning existing nomenclature ; but 

 on points of this nature there must exist ditferences of opinion, 

 and other workers may feel inclined to regard the evidence in a 

 different light. Pastor Wallengren does not allude to the ' Sys- 

 tema Naturae,' ed. xii., in which Linne adds references wanting 

 in the ' Eauna ;' and it should be noted that still other references 

 exist in MS. in his own annotated copy of the ' Systema' in the 

 Library of the Linnean Society. 



The Linnsean collection affords very little evidence. There are 

 in it a moderate number of Trichoptera, but only two or three 

 bear labels in Linne's hand : and, as is usual, there is much un- 

 certainty as to whether they are now on the specimens to which 

 they were originally attached. 



Phetganea steiata(No.1483). — Up to the year 1851 no author 

 had separated by sure structural characters the two species which 

 now generally bear the names of Fh. grandis^ L., and striata, L. 

 In that year Hagen demonstrated most clearly the existence of 

 two very distinct species, to the second of w^hich he applied the 

 name striata, retaining that oi grandis for the first, in which he 

 has been generally followed. Considering the great outward re- 

 semblance of these two species, and that Linne was unaware of 

 the importance of the structural characters in Trichoptera, it has 

 always been with me doubtful that he could possibly have sepa- 

 rated the two ; and it is rendered still more doubtful in my 

 mind from the interposition of a small and very different insect 

 between them (cf. my 'Eevision and Synopsis,' p. 24). Still 

 there does exist (although Hagen states the contrary) in 

 Linne's collection a $ of that which we now term striata bear- 

 ing a label (No. 738) in Linne's hand : it is considerably rubbed, 

 and in that condition is not opposed to the words of the de- 

 scription, and the objections stated by Pastor Wallengren are so 

 far not well grounded. I find it impossible to accept the latter's 

 views as to the identity of striata with Neuronia ruficrus. The 

 w^ord subtestacese," even with the addition of " sive fuscse," 



