8 



THE BRITISH NATURALIST. 



[January 



still, refers Haworth's migadactyla, a species with white wings and white 

 body, to the same species. Now we have in Britain, I suppose, only three 

 species with really white wings and white body — -pentadactyla, 

 galactodactyla and spilodactyla, two others are perhaps approximately 

 white, but only so in the slightest degree — tet?~adactyla and baliodactyla. 

 But Haworth describes three white species — pentadactyla, galactodactyla 

 and migadactyla. He also describes tetradactyla, but not baliodactyla. 

 This latter species is not white, and does not agree with Haworth's 

 description : — ' Alucita (the chalk-pit plume) alis fissis albidis fusco 

 maculatis, anticis fissis posticis tripartitis, fuscis, Fab.' ' Habitat, Cretacis, 

 ut valde infrequens.' ' Statura prsecedentium. Corpus album. Alae 

 anticae albidae, fusco- maculatae, posticae fuscse. Pedes albi, fusco maculati. 

 Fab.' (' Lepidoptera Britannica,' p. 478). There is no British species 

 but spilodactyla, to which this description could reasonably apply, and 

 Haworth's remark : — ' Perhaps the last two (pallidaclyla and migadactyla) 

 species would more naturally range immediately after galactodactyla ' 

 applies very strongly to spilodactyla. How Wocke could suppose that 

 one of our white species might possibly be synonymous with Hiibner's 

 ochrodactyla I am perfectly at a loss to understand. The migadactyla of 

 Haworth is prior to the spilodactyla of Curtis. I have left entirely out 

 of account the Fabrician migadactyla, as there may be a white Con- 

 tinental (not British) species to which the description might apply, but 

 that does not influence Haworth's use of the name for our 

 species " (" Entomologist's Record," etc., Vol. I., p. 93). 



Imago — The fore wings are divided into two plumules by a deep cleft, 

 which reaches nearly to the centre of the wing, apex of both plumules 

 acute, the second plumule falcate. The ground colour is white; the fore- 

 wings are shaded with fuscous along the base of the costa. On the costa, 

 directly above the fissure, is a distinct blackish streak, from which a fuscous 

 shade runs directly to the extremity of the fissure ; a second fuscous shade 

 runs obliquely from the extremity of the former one towards the anal 

 angle, the two thus making an angulated fascia ■ another but much fainter 

 angulated fascia crosses the plumules between this and the apex of the 

 wing ; a third faint fuscous shade occurs near the apex of the upper 

 plumule ; the median nervure and inner margin are narrowly fuscous ; 

 the fringes white. Hind-wings divided into three plumules which are 

 grey in colour, the outer part of the fringes white, the basal part grey. 

 Stainton's diagnosis of this species is as follows: — " g'" — 10"'. Fore- 

 wings whitish, with a grey blotch at the base, and a grey blotch at the 

 fissure; fringes white, spotted with grey. VII." ("Manual," II., p. 

 444). I have already quoted Haworth's original description of miga- 

 dactyla. 



Curtis' original description of this species under the name of spilodactyla 

 is as follows : — " White, inclining to straw colour. Antennas subochra- 



