THE TYPICAL FOBM OF ACRONYOTA LBPORINA. 101 



With the characteristic marks darli. " (2) A grey form described {op. dt.) 

 as very much suffused, with scarcely any trace of the white colour 

 which characterises the type, the colour of the anterior wings of a dark 

 uniform grey, the black markings of necessity less pronounced," etc. 

 This is the form which Prest says "occurs at York, all of the var. 

 bradyporina;" Dobree (teste Tutt) says that this form occurs through- 

 out the East Riding, and Mr. Tutt notices it from Essex and the New 

 Forest ; whilst Cooke (teste Tutt) records it from Liscard, a locality not 

 far removed from Liverpool ; it is further the form that Newman 

 figures, and refers to var. bradyporina, St. (British Moths, p. 251, fig. 

 2). It is, one supposes, also the lower insect photographed by 

 Mr. Main, and badly reproduced, to illustrate Mr. Mansbridge's remarks 

 (Ent., xxxviii., fig., p. 289). 



The actual range of these two forms in the British Isles must be 

 remarkably patchy ; it never seems to have been worked out, but, from 

 Cooke's remarks (supra), and specimens under examination, one would 

 suppose that the grey form must occur over the greater part of the 

 Lancashire and Cheshire district under consideration, although Mr. 

 Mansbridge asserts that " the typical insect occurs everywhere in North 

 Cheshire and South Lancashire where birch is found, but does not 

 seem to be abundant in any of its localities, among which may be 

 mentioned Delamere Forest, woods near Hale Bank, Knowsley Park, 

 and the mosses between Prescot and Ormskirk ; " yet this must include 

 .the district where Nicholas Cooke obtained the "grey " form ; it is this 

 form that he contrasts with the white Scotch (Laggan) form; and it is 

 surely this quasi-"local type" that (in one of its palest forms) Mr, 

 Mansbridge figures and describes. It is also quite true that it "is 

 scarcely darker or more irrorated with black than specimens from other 

 parts of England," e.g., Essex and the New Forest (teste Tutt), but 

 surely var. (or "ab.'' m sens, strict.) melanocephala is a suffused form 

 of this grey race, with which, indeed, Mr. Mansbridge indirectly shows 

 it to be connected by intermediates. 



It has already been noted that Newman calls this grey form brady- 

 porina, Stephs., whence no doubt the name obtained general currency 

 in Britain, and Staudinger in his Catalog, 2nd ed., p. 77, quotes it as 

 bradyporina, Tr. (non Hb.) and diagnoses it as " alls anterioribus 

 grisescentibus," and gives as its habitat " north Germany," etc. Mr. 

 Tutt, following out the popular idea, and Staudinger's lead in this 

 matter, includes all the specimens of the grey race under the name 

 bradyporina, Tr. So far our knowledge is clear, but now that Mr. 

 Mansbridge has selected an extreme example of the grey form for 

 special treatment, and named it, I wish to ask whether this extreme 

 form is not really bradyporina, Tr., and whether the race itself ought 

 not to be called var. grisea. 



Mr. Mansbridge describes his aberration thus : 



Differs from the type* as follows : Forewings in both sexes strikingly suffused 

 with fuscous, and with all the normal markings intensified ; thorax black, abdomen 

 blackish, not so dark as the thorax ; hindwmgs as in the typef. 



Treitschke describes (Die Schmett. von Enropa, v., pt. 1, p. 9) 

 bradyporina as follows : 



* We must assume this to mean Mr. Mansbridge's type, i.e., the grey form, not 

 the Linnean type which he seems not to know, nor to have looked up the 

 description. 



t The hindwings in the Linuean type are almost pure white. 



