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Show 3()8 SEXUAL SELECTION. PAr.T II. generally redder but rather duller than the females, the latter being coloured of a more or less splendid golden green. On the other hand, in one species the male is golden-green, the female being richly tinted with red and purple. In the genus Esmeralda the sexes differ so greatly in colour that they have been ranked as distinct species : in one species both are of a beautiful shining green, but the male has a reel thorax. On the whole, as far as I could judge, the females of those Prionidre, in which the sexes differ, are coloured more richly than the males; and this does not accord with the common rule in regard to colour when acquired through sexual selection. Fig. 1:i. Cbalcosoma atla~. Upper figure, male creaucctl); lower figure, female (nat. size). trichia and Trichius, the male of the !utter being more obscurely coloured than the female. In Tillus elongatus the·.male is black, and the female always, as it is believed, of a dark blue colour with a red thorax. The male, also, of Orsodacna atra, as I hear from Mr. Walsh, is black, the female (the so-called 0. ruficollis) having a rufous thorax. CIIAP. X. Fig. 18. Fig. 19. VOL, I. COLEOPTERA. 369 Dipelicus cantori. Onthopbagua rangifer, enlarged. 2 B |