BKITISH LEPIDOPTERA. 



Variation. — More perhaps has been published on the variation of 

 this, than any other Anthrocerid, species. It is not confined to any 

 particular kind of habitat, nor to one condition of environment, 

 except that it is rarely (if ever) found off a calcareous soil, and flourishes 

 in the plains of Central Europe, the warm valleys of southern 

 Europe and the high Alps to 9,000 ft. It extends from Sicily 

 to the Arctic Circle, and from the west shores of Ireland to the 

 borders of China. In many places it is a roadside species, in otbers 

 it haunts grassy openings in woods, in others, exposed hillsides, and 

 yet again is found high on Alpine pastures. Under such varied con- 

 ditions it is not surprising that the species should exhibit consider- 

 able variation, and much difficulty has existed as to the determina- 

 tion whether certain forms were races of this, or really distinct, species. 

 The scales are readily removed, but the diaphanous appearance of 

 some individuals is not altogether due to their being somewhat worn. 

 There is, however, considerable variation in the size, as well as in the 

 intensity of the coloration of the red blotches of the fore-wings, and, 

 frequently, there is a tendency for the blotches to decompose into the 

 spots characteristic of the " spotted" groups. Zeller described (Isis, 

 1840, p. 137) a series of forms illustrating this phase of variation : 

 (a) With 1 filling up the space between the costa and subcostal nervure, 

 2 + 4, entirely confluent, forming a spot anteriorly rounded, and 

 filling up the space between median and subcostal nervures, 3 + 5 + 

 6 united to form a third spot, pointed towards the base and much 

 expanded anteriorly. (6) With the spot 2 + 4 more or less deeply 

 emarginate on both sides, (c) With the spot 3 + 5 slightly exca- 

 vated on both sides, (d) With the excavation between 2 and 4 

 deepened so that the spots are separate, 4 forming a small spot or 

 point towards the base of 2. (e) With the excavation between 3 + 

 5 deepened, so that they become separated. (/) Like b, but with a 

 short, faint, red streak between the subdorsal nervure and inner 

 margin. (//) With the usually dark nervures of the type form covered 

 with red scales, so that the red blotches are entirely united into a 

 single red blotch = the passage to polyr/alae, Esp. Zeller adds that 

 there are connecting links between these aberrations in which, on one 

 or both wings, spots 3 and 5, 2 and 4 are connected by a slender 

 thread of red. He also notes that the forms d and e do not show half 

 as much red on the fore-wings as the typical form a does. Nearly all 

 the specimens of the forms b, c, d and e have on the hinder margin 

 of the united last pair of spots, a deep excavation, and the margin is 

 not gradually lost in the ground colour. The portion which belongs 

 to the upper spot, 5, is always of a much deeper red. Other speci- 

 mens of the form I) are without this emargination of the securiform 

 spot. On the other hand, in some examples the red scales cover the 

 nervures, and make the central portion of the fore-wings entirely 

 red, occasionally extending even to the inner margin at the base. 

 Freyer notes (Stett. Ent. Zeit., 1844, p. 85) that the securiform 

 spot varies, being broader, larger, and more lost in the ground 

 colour in some specimens than others. All authors are agreed that 

 the south European specimens are as a rule more thickly scaled than 

 those of more northern latitudes and high altitudes. Herrich-Schaffer 

 says that the southern and Alpine examples have frequently a more 

 shaggy-haired abdomen, which conceals the shorter steel-blue scales. 



