FURTHER NOTES ON HESPERIID CLASSIFICATION. 9 



series reveals the fact that the wings of armoricanus are less 

 elongate in this respect, and that the butterfly is more compact 

 (" plus ramasse, si Ton me permet cette expression ") ; the con- 

 tour of the wings approaching that of onopordi, and differing 

 from that of alveus. 



Upper side, coloration : armoricanus less deeply black, and greyer ; 

 white spots more conspicuous, especially on the hind wings ; 

 median band, hind wings, much accentuated, and the colour pure 

 white or nearly so (more resembling in this respect cirsii) ; while 

 in alveus it is brownish or greyish. 

 Under side, fore wings : In alveus more or less blackish, especially 

 outside the " Q" mark; in armoricanus grey, and more evenly 

 distributed. 



Hind wings: In alveus, ground colour yellow-olive-green, uni- 

 form, or nearly so ; in armoricanus, tint at once more variable 

 and less uniform ; ground colour greyish, yellowish, or reddish, 

 with deeper brown markings, especially at the costal margin, 

 and outside the median band of spots. Nervures clearly denned 

 either in yellow or pale grey. In alveus the nervures do not 

 stand out at all, or much less definitely. Median band relatively 

 much narrower in armoricanus. Outer margin slightly convex 

 in alveus, thus giving the basal band of spots a broader and more 

 conspicuous appearance than in armoricanus. 

 The fringes, palpi, and antennae exhibit no appreciable diffe- 

 rences, but the abdomen of armoricanus is apparently more 

 elongate than that of alveus, reaching beyond the anal angle. 



Dr. Reverdin also remarks en passant that armoricanus and 

 cirsii have been confused together owing to the prominence in 

 both cases of the nervures on the under side of the hind wings. 

 But though, as M. Oberthiir says, the former resembles in some 

 respect the latter insect, the intradiscoidal spot on the upper 

 side of the fore wings in alveus and armoricanus is convex 

 towards the outer margin ; in cirsii it is rectilinear. This 

 peculiarity was discovered by my lamented correspondent, the 

 late M. F. Delahaye, of Angers, and appropriately enough it is 

 designated by M. Marcel Rehfous, "la signe de Delahaye" — 

 " Delahaye's mark." 



But for the collector anxious to identify his unnamed Hes- 

 periids of this group in the field, or (if labelled) in the cabinet, 

 there is an easier method of determination than structural or 

 superficial characteristics, as in the cognate cases (with the 

 additional clue of latitude) of H. malvce and H. malvoides. For, 

 whereas armoricanus is certainly double-brooded in the majority 

 of localities, alveus has but one emergence. Armoricanus flies in 

 May and June, and the first generation should be exhausted 

 before alveus is on the wing from mid-July to the end of August ; 

 the second emergence takes place in late August and September, 

 though in normal seasons possibly the laggards of alveus overlap 

 the first of the new armoricanus. 



