AttTriROCERA HIPPOCREPIDIS* 533 



the 6th spot on the anterior wings, the one towards the anal angle, 

 is generally small, with a coloured nervure passing through it ; the 

 under surface of the anterior wings with the disc entirely red, and 

 the maculations not defined. Above, the anterior wings are blue- 

 black, with six red spots, disposed as in A. Jilipendulae, and the 

 posterior red, with an undulated greenish-blue margin ; the abdomen 

 immaculate (Stephens, Illustration* JiritMt Entomology, etc., i., p. 109). 



IMAGO. Anterior wings, 28-36 mm., blue-green, or green in colour, 

 with six crimson spots, the lower of the outer pair usually ill-developed, 

 often with a dark nervure passing through it. Posterior wings 

 crimson, with a narrow marginal border (but broader than in normal 

 A. Jilipendulae'). 



SEXUAL DIMORPHISM. Males expand from 23 mm. -32 ram., females 

 from 26-36 mm., but on the whole the females are considerably larger 

 than the males. The males have also the 6th spot much less 

 defined than the females. Of two examples with it entirely absent, 

 both are males, of 20 others, in which it is represented by a few red 

 scales, all are males, whilst in 32 others, arranged in order following 

 the ill-developed nature of this spot, only two are females, so that 

 of the 54 which show spot 6 with its least development, two only are 

 females. Of 150 other examples, the 20 in which the 6th spot is 

 almost as large and well-developed as in typical A. Jilipendulae, are all 

 females. The males also have, on an average, a wider marginal band 

 to hind-wings than the females, and, taken as a whole, one is struck with 

 the specialisation of the sexes, the males in the direction of A. tri/olii, 

 the females in the direction of A. Jilipendulae. Bateson, who had the 

 most distinctly five-spotted example we have ever captured, with no 

 trace of a 6th spot on the upper, and only a few red scales in its 

 position on the under, side, reported it as having genitalia similar to 

 those of A. fttipendulae. 



VARIATION. Stephens says that, like A. Jilipendulae, this species 

 varies considerably, from the spots being more or less confluent or 

 obliterated. We have seen no really good confluent aberrations of 

 this species, and in our series of 280 specimens, only two are well- 

 defined examples of ab. cytisi, i.e., analogous with the ab. cytisi, Hb., 

 of A. Jilipendulae, two or three others having the central pair of spots 

 united. One male example has the right fore-wing 9 mm. in expanse, 

 the corresponding left fore-wing being 12-5 mm. Another male has 

 the left hind-wing with a hole punctured through it, as if eaten out by 

 an ichneumon grub, another has the right fore-wing rounded apically, 

 and with a projecting point in the centre of the outer margin }-, 

 another has the right hind-wing 6 mm. long, the left 9 mm., whilst 

 others exhibit considerable modification in the narrowing or apical 

 rounding of the fore-wings. One example has the right pair of wings 

 of full size, but composed of whitish (almost transparent) membrane, 

 with the ordinary red spots and hind-wings faintly pinkish, the left 

 pair of wings normal. Another is distinctly pallid, ab. pallida, n. ab., 

 the ground colour of the fore-wings greenish-grey, the spots of fore- - 

 wings and hind-wings pale pinkish-red, the marginal border of a 

 similar greyish hue to the ground colour of the fore-wings. In two 

 or three examples the bases of the hind-wings are orange, and one 

 other is somewhat yellowish on the outer margin of the left hind- wing. 

 A yellow form, ab. luttiswns, n. ab,, is described by Stephens (lilies., i., 



