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VII. On the genus Acentropus. By J. W. Dunning, 

 M.A., F.L.S., &c. 



[Read 4th March, 1872.] 



I HAVE to announce the capture of Acentro2yus almost in 

 the heart of London, about a furlong from the Regent's 

 Park canal. Between nine and ten o'clock one evening, 

 in the latter half of July, 1871, an insect attracted my 

 attention, chiefly by the peculiarity of its flight round the 

 lamp near which I was sitting ; in colour and general 

 appeai-ance it was insigniflcant enough, and might have 

 been a small Crarabus ; but it had not the weak and vacil- 

 lating motion of a Gramhus, for it flew with decision and 

 in circles, or rather semi-circles, alighting constantly on 

 the table for a moment, then flitting ofl' to perform 

 another round. When it sat for an instant, the horizontal 

 and deltoid pose of the wings, and an indescribable sprawl 

 of the legs, reminded me of Hydrocampa. I had not 

 recognized the insect as Acentropus, and it was only on 

 the following morning, when I had killed the specimeu, 

 that I found out what it really was. But the living insect 

 was certainly to my eye a moth, and it produced upon 

 my mind the impression of a Cramboid Hydrocampa. 



In 1791, Olivier gave a short description of what is 

 supposed to be our insect ', he placed it in his third section 

 of the Order Neuroptera, and called it Phryganea nivea; 

 at the same time he remarked, that the Phryganece form 

 a link between the Phalwnw and other four- winged insects. 

 Latreille followed Olivier, and apparently was acquainted 

 with P. nlvea only from Olivier's desci-iption. 



In 1829, Stephens introduced into his ^Systematic 

 Catalogue of British Insects,' the name " Acentria nivosa 

 {Ph. nivea, Oliv. ?)" and placed it in the Neuroptera, 

 amongst the Perlidce. In the same year, Curtis in his 

 * Guide to the Arrangement of British Insects,' introduced 

 the name Acentropus Garnonsii, as distinct from Acentria. 

 And in 1833, Stephens, in the second edition of his 

 'Nomenclature,' gave Zancle llansoni as distinct from 

 Acentria nivosa. But there was no description of any of 

 these. 



In 1834, in vol. xi. of * British Entomology,' Curtis 

 characterized the genus Acentroims, and on pi. 497 he 



TKANS. ENT. SOC. 1872. — PART II. (mAY.) 



