2o6 



THE BRITISH NATURALIST. [October 



scarcely be in doubt about Haworth's. The name might well read : — 



Heterodactyla, Haw., VilL 

 " Teucrii, Greening. 



Haworth assumed (from description) that Villers' species was the 

 same as his own, just the same as he assumed his didactyla was the 

 'LinriddSin didactyla, which we now well know, could not have been 

 the case (because didactyla, Linn, is not a British species), yet 

 Haworth's didactyla is British, and would replace distans, were there 

 not already another plume named didactyla. Linn. On this ground 

 alone, therefore, Haworth's heterodactyla, which we know represents 

 teiwrii — both from description and from Dr. Mason having Haworth's 

 actual type with the name attached — must in correct nomenclature, 

 replace the latter name of teucrii, whilst Villers' heterodactyla, about 

 which Mr. Briggs very properly expresses so much doubt, could be 

 ignored, or ' Villers (?) ' added after the name." 



Imago — The imago belongs to the dark-coloured group of Oxyptili 

 and is a most beautiful insect. The anterior wings are divided into two 

 lobes of a rich fuscous-brown colour with the outer edge of the costa 

 margined with white, and the inner narrowly paler. In the centre of 

 the wing is a small white longitudinal mark, a white spot at the end 

 of the fissure, whilst tv/o white fasciae cross the lobes, the inner 

 making an acute angle near the termination of the fissure, the other 

 being almost parallel to the hind margin. The posterior wings are 

 divided into three plumules, the two upper are dark brown, the 

 third pale, and with a distinct double tuft of black scales, the inner 

 large, the outer near the tip of the wing and very small. The head 

 and thorax are of the same colour as the fore-wings, the abdomen as 

 the hind wings but annulated with white ; the legs are also dark-brown 

 annulated with white. Haworth's diagnosis is as follows: — " Alis 

 patentibus fissis, nigris, macuiis albis." Mr. C. G. Barrett gives the 

 following: — Heterodactylus, Haw. {teucrii, Greening), which was at 

 one time mistaken for hieracii, is, perhaps, the largest of the group, at 

 any rate, its wings are decidedly broader, and from its dark colour and 

 bright white markings, it is by far the most handsome. Its costal 

 margin is much rounded, tips long and drooping, fasciae fairly broad 

 and brightly defined, and the inner (dorsal) margin of the fore wings 

 is edged with bright white cilia, in which are three black dashes. 

 The third feather of the hind wing has a large blackish tuft, and the 



