282 Mr. J. W. Dunning on Acentropus. 



May. In this country Boyd found it at Cheslmnt on the 

 1st June ; and Corbin at Eingwood from the beginning of 

 June to the end of August. The latter "s^^iter mentions 

 various enemies that prey upon Acentropus. F. Walker 

 and J. P. Barrett both record instances of the moth being 

 attracted to light. Syme's capture of the insect in Scot- 

 land is interesting as corroborating Leach ; he mentions 

 Potamorjeton Jiliformis as the species of pondweed which 

 it frequented, whilst J. J. Walker mentions P. pectinatus. 

 Boyd found pupte at Cheshunt on the American w^eed, 

 Anacharis alsinastrum ; the moth and the Anacharis 

 Avere abundant, Potamogeton was very scarce in that 

 locality ; but there is as yet no evidence that the larvfe fed 

 on Anacharis. The prominent lateral spiracles are not 

 confined to the pupa? of Acentropus, but occur likewise in 

 the pupffi of some at least of the Hydrocampidce. As to 

 the presence of tibial spurs in the perfect insect, see Snellen's 

 observation quoted by Hitsema (Tijd. v. Ent. xvi. 19, n.), 

 confirming what is stated ante, p. 130. Wallengren, in 

 his " Skandinaviens Pyralider," published in the 28th vol. 

 of the Stockholm " Ofversigt," places Acentropus in and 

 at the end of the family Botydce, distinguishing it (at 

 p, 973) from the other sixteen genera by the characters 

 " legs without spurs ; female wingless ; ocelli and superior 

 palpi wanting;" or, as it is expressed at p. 1009, "legs 

 short and thin, without spurs ; the female wdth short 

 pointed rudiments of wings." According to the same 

 author (who thus confirms Reutti's statement, ante, p. 138) 

 " the female is on the move by night, and swims on her 

 back under the water, and for pairing she also draws doAvn 

 the male, which flies just over the surface of the Avater, and 

 also runs pretty quickly on the water ; the male is chiefly 

 on the move by night, but flies also by day." Wallengren 

 (referring to Nolcken's paper) adds that there are probably 

 several species of the genus, and that sometimes winged 

 females occur ; he however cites Kolenati's figure of A. 

 NevcB as identical Avith A. niveus. With reference to 

 NcAvman's remark (Zool. S. S. 3122) that the conflict 

 betAveen the tAvo descriptions of the eggs, noticed ante, 

 p. 133, is " sufficient to prove that the eggs described were 

 scarcely those of a single species," I may observe that 

 NcAvman has failed to notice that the conflicting descrip- 

 tions Avere given of one and the same batch of eggs, de- 

 posited on one and the same Potamogeton-lesif. 



