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Show 6 MR. GUY A. K. MARSHALL ON THE [Jan. 19, probably largely influenced by the surroundings, such as soil, leaves, &c, in which the insect habitually rests. > In addition to these there are instances in which a species may show seasonal modifications peculiar to itself. Ior example in T. pleione, Klug, the area of the discal yellow is reduced in the dry season, which, however, does not occur m its^ near allies. Again, T. hetaera, Gerst., exhibits a marked reduction of the crimson apical patch; whereas in the dry-season form oi T. regina, T i m. the purple patch is, if anything, rather larger and brighter, owing to the reduction of its black borders. _ With regard to the nomenclature adopted in this paper ni> object has only been to give a more or less clear definition of the species which constitute the genus Teracolus, and I have not attempted in any way to apply a system of nomenclature to the variations, whether local or otherwise, to which these species may give rise. Besides, at the present time the classification ot such variations is in a somewhat chaotic state, at least so tar as exotic Lepidoptera are concerned, and the same form may be referred to by various authors either as a true species, subspecies, local race, climatic variation, variety, or seasonal form. This is, no doubt, due to the lack of any standard definition, so that each man is a law unto himself in the matter. However, there is no doubt that it will be necessary to apply names to a few of the more marked local forms, which I regard as incipient species ; and in such cases the trinomial system of nomenclature seems to m e to be the clearest and most satisfactory, as we thus keep in view the gradual evolution of the parent species. But at the same time I cannot inveigh too strongly against the idea that every slight deviation from the typical colouring of a species must be encumbered with a Latin name, which appears to m e to be thoroughly pernicious, and stultifies the very object of nomenclature, which is to elucidate and not to confuse. This variety-mougering has reached such a pitch in Europe that even artificial varieties are adorned with " scientific" names, which has certainly not been done in the interests of science, but is due partly to a misguided ambition on the part of the gentlemen who coin the names, and partly to trade motives. With regard to the naming of seasonal forms, I can see no more necessity for it than for the naming of sexual forms ; and a simple solution of the difficulty would be the adoption of three standard signs or letters, to signify wet, dry, and intermediate forms respectively, in the same way that signs are used to distinguish the sexes. 1. TERACOLUS SUBFASCIATUS. Teracolus subfasciatus, Swainson, Zool. 111., Ins. ii. p] 115 (1823). Ptgchoptergx bohemanl, Wallengren, K. Sv. Vet.-Akad. Handl ; Lep. Shop. Caf. p. 18 (1857). On the eastern side of South Africa this swift-flying Teracolus |