12 



At the present day it is scarcely necessary to remark that these 

 numerical names were lauciful, all the species having the anterior wings 

 Di-dactyle, and the posterior wings Tri-dactyle, so that with the ex- 

 ception of Pcntadactyla, all the others with numerical names were incor- 

 rectly designated. 



Indeed, it would appear that Liiuie had lacked some of his usual 

 critical acumen when treating of these insects, since of Tesseradactyla 

 he says, "Aire inferiores tetradactylae;" and of Pentadacti/la he writes, 

 "Alse inferiores qumquepartitje." 



Moreover, his Tridactyla of the Systema Naturce has assigned to it 

 the very description which, in the 'Fauna Suecica, belongs to Tetradac- 

 tyla, and for the Tetradactyla of the Systema Naturce a new description 

 is formed, though reference is made to the Tetradactyla of the Fauna 

 Suecica as a synonym. 



To one species in the Fauna Suecica Linne assigns a food-plant, 

 thus of Didactyla he says, " Habitat in Geo rivali." 



Now his description of Didactyla is short, and the insect belongs 

 to a group of numerous closely allied species. 



DeGeer, in the first portion of the second volume of his memoirs, 

 gives a long and detailed history of this Didactyla, of which the larva) 

 feed in May on, and in the flowers of the Geutn rivale. Of the larva?, 

 mode of pupation and pupa, De Geer gives a long and very interesting 

 history (see pages 261 — 266). 



Zeller, in his monograph of the Pterophoridse in the Isis of 1841, 

 pointed out that the Didactyla of Linne was probably the species more 

 generally known as the Tricliodactyla of Hiibner, but that before super- 

 seding the latter name it would be desirable, by the discovery of the larvie 

 on the Geum rivale, to prove, beyond all cavil or dispute, what was the 

 veritable Linnsean Didactyla. And in the sixth volume of the Linncea 

 Fntomologica (p. 353), published in 1852, he once more called attention 

 to the importance of again finding the larvae on the Geum Rivale which 

 had been so carefully described by De Geer in 1771 (more than eighty 

 years previously .') 



This has now been accomplished, thanks to the perseverance of 

 Dr, Schleich, of Stettin, and in the first part of the Stettin Entomolo- 

 gische Zeitung for the present year, Ave have at p. 96 the following note: 



"On the earlier stages of Pterophorus didactylus, L. Ev. (tricliodactylus, Hiib.) 

 —By Dr. Schleich." 



"Having taken the imago in great plenty in June and July 1862, in 

 a small meadow between Grabow and Bredow, hardly a quarter of an 

 hour's walk to the North of Stettin, I succeeded in May, 1863, in find- 



