86 



[April, 



xiv, 164-166, with the material upon which they were based, 

 has, to my great regret, disclosed some marked discrepancies between 

 them. Oiu- friend's principal reasons for separating these supposed 

 species were (1) that verrucella, Hb., has an elevation of red scales 

 just outside, but not upon, the thick black first line, whereas ruhro- 

 tihieUa, F.R., has no corresponding tuft of raised scales, either red 

 (p. 165), or black (p. 166) ; (2) that rvhrotibiella, F.E., has the fore- 

 wing decidedly broader from the base, and much more squared behind, 

 than its ally, the hind margin being almost perpendicular, and the 

 anal angle conspicuously filled out. But his specimens show (1) that 

 in both his verrucella and his ruhrotibiella the dark first line, which he 

 obviously thinks is composed of flat scales in both insects, is formed of 

 raised scales, and that a still more conspicuous bar of raised, and 

 remarkably long, rufous or red-brown scales touches its outer edge ; 

 (2) that the differences in the shape of the fore-wings are not 

 constant. Again, my friend failed to notice that whereas, in Hiibner's 

 original and all-imjjortant figure of verrucella, the first line is markedly 

 oblicjue, lie himself describes verrucella, Hb., as having this line " nearly 

 straight and erect," his " erect " being evidently directly opposed to 

 " oblique ! " 



An examination of Barrett's scanty material together with a large 

 number of British individuals, standing in my own and other cabinets 

 as " ruhrotibiella,''' " verrucella,''' " timiidana," &c., and of the lengthy 

 series of " Acrohasis tumidana, Schiff.," in our national European 

 collection, which includes Continental specimens from the Frey, 

 Ragonot, and Zeller collections, has led me to the conclusion that 

 Barrett found " distinctions " where there are no reliable " differences," 

 and that his two supposed species are merely forms of one and the 

 same insect. The late M. Eagonot, who made a special study of the 

 PJiycitidfe of the world, was well acquainted with these and other 

 forms of this Acrohasis (which, as he pointed out, in Ent. Mo. Mag., 

 xxii, 27-28 [1885], should bear the name tumida^ia, S.V., this 

 having priority over both verr^icella, Hb., and ruhrotibiella, F.E.), for 

 he expressly says (oj). cit., p. 28), — " .... ruhrotibiella, F.E., but 

 the latter species varies very much, and I have specimens which agree 

 very well with fig. 73 of Hiibner." Now Hiibner named his fig. 73 

 " verrucella," and it is precisely these two somewhat different-looking 

 forms of tumidana, S.V., viz., verrucella, Hb., and ruhrotibiella, F.E., 

 that Barrett convinced himself were specifically distinct. A long 

 series of A. tumidana, S.V., whether British or Continental, shows 

 a wide range of variation in size, colour, and shape of wing, but the 



