136 Mr. J. W. Dunning on 



settled on the underside of leaves, &c., close to the 

 water's edge." I have already mentioned 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 atten- 

 tion 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 tablecloth ; 

 and Stainton, some years ago, took a female specimen at 

 Lewisham which flew to a gaslight fixed outside his 

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

 seen many dead spacimens 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 Fotamoyeton, by 

 means of a shallow net with a long handle. 



The form originally named Zancle Hansoni by Stephens 

 has been already mentioned as the female ; this form has 

 fully developed wings, and it was not until 1854 that the 

 existence of an apterous form of the female of Acentropus, 

 or one with only rudimentary wings, was established. 

 Simultaneously with the above-mentioned discovery of 

 the eggs, Curtis and Dale found this second form of 

 female ; and the event is somewhat meagrely reported in 

 our ' Proceedings^ as follows: "Mr. Curtis exhibited 

 specimens of Acentropus Garnonsii from Glanville's Woot- 

 ton, including the apterous female," — as if the apterous 

 female, instead of being a novelty, was a familiar creature. 

 The Dorsetshire females (as I was informed by Dale) 

 were not absolutely apterous, but had rudiments of wings. 

 In 1858, Brown found at Burton-on-Trent a pupa from 

 which an apterous female emerged ; the Burton females 

 (as figured by Brown) were absolutely apterous, without 

 a vestige of wing. In 18G0, Moschler* described A. lati- 

 pennis from a female example from Southern Russia, 

 which was amply winged ; and his description mainly 

 consists of a comparison with another winged insect 

 which he supposed to be the female of A. niveus.'f In 



* Brown (Nat. Hist. Tutbury, p. 401) erroneously attributes the descrip- 

 tion of A. latipemiis to Koleuati. 



t Upon this Brown remarks, that " it is manifest the insect he describes 

 as A. nireus is of the male sex ; the comparative characters are, there- 

 fore, useless." In other words, Moschler's comparison only shows the 

 distinction between the sexes. I do not quite see, however, why the 

 insect with which the ? latipennis is compared, may not have been a 

 winged female of the Zancle form. 



