142 Mr. J. W. Dunning on 



men which was ticketted " alba, Oliv. ; " * there is no 

 Phri/ganea alba of Olivier, but alba, is the first word of 

 the diagnosis of Phryganea nivoa ; and I presume, there- 

 fore, there must have been an oral tradition attached to 

 Haworth's, and, perhaps, other specimens, that they were 

 the '' frygane blanche " of the French authors, and by 

 this means Stephens was satisfied that his Aceyitria was 

 identical with Olivier's insect. Perhaps some of our 

 friends on the banks of the Seine will take the pains to 

 re-discover Olivier's nivea; as Milliere says "it is hardly 

 known in France." And, at all events until such re- 

 discovery is made, it must remain a matter of consider- 

 able doubt what the PJiryganea nivea really was. But if 

 it was not identical with the species (or one of the 

 species) of Acentropus which we have in this country, it 

 has dropped out of knowledge altogether ; it is a name, 

 and nothing more. 



Brown's view is, that Curtis's Garnonsii is the niveus 

 of Olivier ; he attributes to this species the specimens 

 obtained by Dale and Curtis at Glanville's Wootton, and 

 by himself at Burton-on-Trent; " the female (he says) is 

 apterous." And speaking of A. Hansom, he says that 

 the female '^ so far from being apterous, is furnished with 

 wings of twice the area of those of the male.'' Now 

 Brown admits that, as regards the males of Garnonsii and 

 Hansoni, " the difference is so slight, that, if specimens 

 of the two species once become intermixed in the cabinet, 

 it is almost impossible to separate them ; " and I venture 

 to say that, but for his belief that the female of one is 

 always amply winged, and the female of the other always 

 without wings, Brown would not have dreamt of regard- 

 ing them as two species. The only ground alleged for 

 separating the two is, that the males being indistinguish- 

 able, one has a winged, and the other an apterous female ; 

 the argument is, that at Glanville's Wootton and Burton 

 only the apterous female is found, and at London and 

 Reading only the winged female is found. And Speyer 

 says the female seems to occur of two forms, " which, 

 perhaps, belong to different species." 



But is this the case ? Let us look into this a little more 

 closely. It is quite true that apterous females (or rather 



* The identical specimen was exhibited by Westwood when this paper 

 •was read ; it is unquestionably a male Acentropus Garnonsii. 



