278 Mr. J. W. Dunning 07i the 



of Ritsema, and that Hansoni, Ste., Garnonsii, Curt., 

 Nevce, Kol., hadensis and gervuniicus, Nolck., must all 

 be united as synonyms Avith niveus, Oliv. He then pro- 

 ceeds (p. 109) to discuss the claim of Moschler's lafipe7inis, 

 and shows (as Brown had previously noted) that three 

 out of the six points of difference relied on by Moschler 

 and Herrich-Schiiffer are precisely the points in which 

 the sexes of A. niveus differ from one another, whilst the 

 other three are not really differences at all, but each occurs 

 in specimens that are undoubtedly niveus, and each in 

 others that are undoubtedly latipennis ; and he adds, that 

 a male of latipennis from Sarepta, which he received fi-om 

 Staudinger, was found, on examination, to differ in no 

 single part from Dutch males of niveus. " It is, indeed, 

 somewhat more broad and stumpy-winged than the smallest 

 niveus ; but, compared with the largest specimens, which, 

 are connected with others by the gentlest transitions, I 

 find that the latter are even more stumpy-winged than 

 latipennis.'''' Finally, Snellen concludes (p. 110) that the 

 claims of latipennis to specific rank have nothing but loose 

 screws to rest upon, and that the opinion is well-founded 

 that all the hitherto-described forms of Acentropus com- 

 pose but one species. 



liitsema yields to Snellen, and, in addition to figures of 

 the ^^gi larva, pupa (PI. V.) and male imago, -with 

 numerous details, he figures (PI. VI.) both the amply- 

 winged and the rudimentarily-winged female as two forms 

 o^ Acentropus niveiis. [Some of the numbers on PI. VI. 

 do not correspond with the explanation of the figures on 

 pp. 113, 114 of the text.] 



On the question of the presence or absence of ocelli 

 {vide Tr. Ent. Soc. 1872, p. 129) Pitsema is silent. 

 Snellen speaks of their absence ; whilst, as to tibial spurs 

 or spines {vide ib. p. 130), Snellen corroborates the ob- 

 servations of Nolcken, Speyer and Westwood, that the 

 spurs, though small and difficult to discover, do really 

 exist. 



It will be remembered that Eeutti observed {vide ib. 

 p. 138) that the wingless female swims on her back under 

 w^ater by night, that coition takes place in the water, the 

 female laying hold of the male and dragging him down 

 Avith her. Pitsema, however, says (Tijd. p. 95 j that "the 

 pairing appears to take place soon after the emergence of 

 the moths, on the surface of the water;" and he suggests 

 (p. 89, n.) that the pair observed by Peutti had been 



