THE ENTOMOLOGIST. 157 



descending again immediately, so that their feet were almost 

 always touching the water. Barrett ' found some faggots sunk 

 with stones in one corner of a pond, leaving some of the twigs 

 above water; and on the under side of these twigs Niveus 

 swarmed, sometimes clustered four or six in a bunch ; they 

 were very sluggish, and, if knocked off a twig, only buzzed 

 along the surface of the water till they found another.' 

 Ritsema describes them as sitting by day on the stems of 

 plants close to the water, and when disturbed coming quickly 

 to rest again ; but in the evening flying nimbly in large 

 circles over the surface, touching the water itself, and settling 

 but rarely. Corbin describes the flight as most peculiar, ' as 

 it never seems to leave the surface of the water, but swifdy 

 flutters its tiny wings, and in the dusk of the evening looks 

 almost as if it was swimming about here and there ; . . . . but 

 in the daytime it will be found settled on the under side of 

 leaves, &c., close to the water's edge.' I have already men- 

 tioned that it was the circular flight of the insect (a male) 

 round a lamp and over the surface of a table, which first 

 attracted my attention to the specimen which gave rise to this 

 paper. De Graaf captured two males which were similarly 

 attracted to a lamp, and performed their antics on a table- 

 cloth ; and Stainton, some years ago, took a female specimen 

 at Lewisham, which flew to a gas-light fixed outside his 

 house. Brown, Dale, and Barrett, all mention to have seen 

 many dead specimens floating on the pond-weed, or on the 

 surface of the water; and during the daytime, Knaggs and 

 M'Lachlan found that the living specimens might readily be 

 fished out from off the Potamogeton, by means of a shallow 

 net with a long handle." 



This is all that is known of the life-history of Acentropus. 

 The hereafter may add further details, but can detract 

 nothing from the value of these. It will, perhaps, be expected 

 of me that I should contest Mr. Dunning's conclusions, since 

 he seems to regard them as antagonistic to my own ; but 

 really there is no necessity for this. I cannot doubt, and 

 therefore will not dispute, Mr. Dunning's facts. Indeed, I 

 have no disposition to duubt the salient points of the sum- 

 mary ; they are in perfect harmony with my own foregone 

 conclusions. For instance, three competent observers — 

 IJerrich-Schaffer, Mr. M'Lachlan, and Dr. Knaggs — find 



