THE ATHALIA GROUP OF THE GENUS MELITiEA . 265 



distinct, but the resemblance to a W ceases altogether in the 

 male, though remaining in the female, the four strokes in the 

 former being merely a slightly wavy line. Dictynna is slightly 

 variable, but the first two strokes are generally distinct, the last 

 two frequently so, but there is very little peak. In hritomartis 

 there is none at all ; the four strokes form a rather straggling 

 Greek s. In deione the practical meeting of iiij and iii2 almost 

 entirely does away with the first two strokes, but the third and 

 fourth are fairly distinct, and there is a small peak. In heri- 

 salensis these first two are represented by a short, straight, or 

 curved line, and the peak is rather smaller. In 2^<^rthe7iie, 

 especially the more northern ones, the peak is very definite and 

 acute, but the first three strokes are almost straightened out 

 into one, the four forming a broad V rather than a W. The 

 other nervures of the fore wing give no characteristics. 



In the hind wing the short pre-costal nervure (marked p in 

 the diagram) presents surprisingly marked characteristics on 

 careful inspection. It forms a sharply defined angle with i at 

 its point of departure, and this may be a right angle, or rather 

 greater, or less. It forms, again, in most species another angle 

 about the middle of its course, which again may be a right 

 angle, or greater, or less ; this latter angle, however, is not 

 sharply defined, but generally slightly rounded, and I speak of 

 it as greater than a right angle if the actual angle is so where 

 the nervure bends, even if it afterwards approaches i. These 

 two angles I refer to as (a) and {b). 



In asteria (a) is a right angle, (b) is greater, no part of the 

 nervure being approximately parallel with the costa ; the second 

 portion does not approach i, and stops well short of the costa. 

 In varia both angles are slightly less than a right angle ; a slight 

 approach is made towards i, but in the female, and sometimes 

 also in the male, the second portion is very long and nearly 

 reaches the costa. In aurelia (a) is slightly greater and (b) 

 slightly less than a right angle, the nervure is nowhere nearly 

 parallel with the costa, but nearly touches it in the female. In 

 typical deione the nervure starts at a right angle and then stops 

 short. In britomartis it is the same, except that there is a 

 very slight curve where the second portion should begin. In 

 dictynna (a) is less than a right angle, and the whole nervure is 

 then curved much like a scythe-blade. In dictynnoides it is 

 much as in dictynna, but the curve is wider and shorter. In 

 berisalensis (a) is a right and (6) an obtuse angle, and at the 

 latter there is a short branch returning towards the base (see 

 diagram). This is also present in athalia, but much less con- 

 spicuously so ; both angles are slightly obtuse, but the second 

 portion of the nervure curves inwards. In parthenie (a) is less, 

 {by greater than a right angle ; there is no return branch, but a 

 slight thickening at (&). 



