TUB VAUIATION OF HeMEKOI'HILA AUuUPTAUIA. I7l 



The Variation of Hemerophila abruptaria. 



By J. W. TUTT, i'.E.S. 



In order that wc should have some record of the aberrations of 

 Hiincroiihila abruptaria, bred by Messrs. Pearce and Southey, and 

 referred to in their notes (ante, pp. l2\-12'-i), they iiave been ,ii^ood 

 enough to place the spechnens in my hands for description. Unfortu- 

 nately, as those notes show, one is unable to deduce any generalisations 

 Ijcaring on heredity. 



it is well known that this species in iiritain offers considerable 

 sexual dimorphism, the males presenting a much darker ground colour 

 than the females, the latter appearing whitish by comparison. The 

 dark markings that ornament the wings are, in typical individuals, 

 usually confined to a pronounced dark blackish (^ ) or umber-brown 

 ($), obli(|ue, roughly wedge-shai)ed patch, commencing on the outer 

 margin just below the apex of the fore- wings and ending about half 

 way towards the inner margin of the wing. This is continued to the 

 inner margin by shading that runs between the elbowed and sul)ter- 

 minal lines. On the hind-wings there is a similarly coloured trans- 

 verse band crossing from the apex to the anal angle, and Ijounded 

 above by a double transverse line, and below liy a cm'ved line that 

 leads to the outer angle of the wing. 



The first stage in the development of the dark markings (as repre- 

 sented by these specimens) is the spread of the dark shading of the 

 hind- wings inwards towards the base, and on the fore-wings outwards 

 towards the anal angle, without, however, any real darkening of the 

 ground colour of those parts of the wings not affected, both sexes 

 retaining in the still i)ale portions of the wings their respective tints 

 of coloration. One small male shows, however, such a general suff"u- 

 sion over the whole area of the wings, the typical marks blending, as it 

 were, into the ground colour. Another male, quite tyj)ically marked, 

 is of a bright brownish coloiu". All these specimens, however, in spite 

 of the tendency to an increase of the darker portions of the wing, are 

 distinctly typical in general appearance, and they do not strike one as 

 presenting a series of slow intermediate stages leading up from the 

 typical to the most extreme aberrant forms. 



Of the dark or roughly unicolorous forms, there are two or three 

 very distinct types : — 



(1). The fore- wings of a bright brown (tending to chestnut brown) 

 hue, tlie basal and elbowed lines paler, the sub-terminal line almost 

 obsolete centrally, but forming a j»ale wavy line at its origin on the 

 costa. The basal area (between the basal line and base of wnig) darker 

 brown, a blackish wedge-shaped spot lying in the second hollow of the 

 elbowed line, and extending outwards to the subterminal line, but not 

 to the outer margin. The fringe alternately light and dark brown. 

 The outer portion of the hind-wings of the same tint as the fore-wings, 

 but gradually becoming darker towards the base, wliich is very dark 

 fuscouB. A pale curved transverse line extends across the wing from the 

 anal angle, almost to the outer margin ; a rather darker shade between this 

 and the median transverse line (i.e., occupying the normally dark area 

 in the tyjxj). The thorax pale (as in the type) ; the abdomen almost of 

 the tint of the hind-wings. This form is confined, in these specimens, 

 to a few females, yet it approaches more nearly the extreme 



