IN THE BRITISH ISLANDS. 85 



Having discovered that par, Hb. was actually a variety of muralis 

 (glandifera), Mr. Warren then further wrote : " In consequence of the 

 confusion which appears to be made between the mealy-looking variety 

 of B. glandifera (muralis), which occurs with the typical form on the 

 coast, and which is sold by the dealers as var. par, and the Bryophila 

 which we take at Cambridge, it will be as well to give the latter, 

 which already has a local habitation, a distinctive name as well. Mr. 

 Stainton, who has seen my series of the Cambridge insect, and considers 

 it certainly distinct from Hiibner's var. par, said, in his joking way, 

 ' call it impar ' : and by this name I propose to distinguish it for the 

 future. I should add that, besides Cambridge, we must now include 

 Cork as a locality. I have seen specimens, belonging to Mr. W. F. de 

 V. Kane, which he informs me were caught in that neighbourhood " 

 (' Entomologist's Monthly Magazine,' vol. xxi., pp. 22-23). 



Mr. Farren writes of the variation of the Cambridge specimens : 

 " Very little seems to be known about Bryophila impar ; comparatively 

 speaking, so few have ever been taken, that entomologists have not 

 had a chance of comparing it with glandifera (muralis}. I have made a 

 careful comparison between a long series of each, the result of which 

 may be interesting to many. There is a very great difference in the 

 general appearance, caused chiefly by impar being thickly covered with 

 black scales, and the blotch near the base, referred to in the table 

 below as No. 2 marking, being so conspicu* isly black. This makes 

 the markings very obscure, and causes impar to be a much darker- 

 looking moth than glandifera. 



A long series of glandifera shows a greater variety of colour than 

 impar. The most frequent form of the latter is grey with a very 

 slight tinge of dull green in it ; and I have specimens varying from 

 this to a very dark bluish-grey, which, with the thick covering of 

 black scales, makes it much blacker than any form of glandifera. A 

 much scarcer form is dark yellowish-green ; and I have one specimen 

 of a very pretty grass-green. The greenish-blue and sandy-coloured 

 forms, as well as two or three shades of green, which are frequent in 

 glandifera, I have never seen represented at all in impar. 



I have been asked several times by correspondents whether I 

 considered impar a distinct species, or a variety of glandifera. There 

 are several points in favour of and against its being considered a species. 

 It will be noticed in the above comparison of the markings, that although 

 there are several features by which it can be readily distinguished 

 from glandifera, yet, with the exception of the basal line, the dis- 

 tinctions lie in the markings of impar being less distinct, and in the 

 case of the subterminal line almost entirely so, rather than in any real 

 difference of shape. 



The only Cambridge specimen anything approaching glandifera 

 that I have seen, was taken by Mr. Alfred Jones, and it forms rather 

 a strong point against its being a distinct species ; it has the basal 

 line broken and the distinct subterminal line, as in glandifera, but it 

 has the blotch near the base very dark, as in impar, and is covered, 

 although not so thickly as is usual, with dark scales. Typical glandifera, 

 or anything more nearly approaching it than this one specimen, I do 

 not think has ever been taken in or near Cambridge ; if it did occur 

 here, I think I should have taken it, as I look very sharply after 

 impar when it is out. 



