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Show 32 MR. GUY A. K. MARSHALL ON THE [Jan. 19, ginal black bars, while on the underside the pink tinge is much fainter than in the full winter form, and the irroration is very sparse. T. hyperides, from Swaziland and V. Nyanza, is a step further in the development of the wet-season colouring, having the black inner marginal stripe more distinct and the underside of hind wings being white; this, again, merges through T. hero into typical T. achine. The series of specimens included under T, subvenosus in the British Museum is an eloquent proof of the difficulty experienced by Mr. Butler himself in discriminating his own species, for they are in truth a "job lot." The species was founded on a specimen of T. achine, which is rather lightly marked above, and has the underside of hind wings white, with the neuration finely black throughout. But the present series shows every development of the upperside black markings, so that some specimens have a strong inner marginal band, while others have none, in spite of the fact that Mr. Butler has founded species on the relative development of this very character. The undersides are equally variable, ranging from the type with black neuration to a specimen in which there is no trace of black, but which is exactly similar to the type on its upperside, thus showing the complete inutility of black neuration as a specific character. T. trimeni I cannot distinguish from typical T. achine. T. gavisa represents the fullest wet-season development of this species, in which all the black markings above and below are strongly developed, and it occurs in suitable localities from Abyssinia to Natal; that is to say, in a moist and wet climate T. gavisa would probably represent the wet-season form of the species, whereas in a drier and cooler place it would be T. achine. For instance, the former is prevalent in the quasi-tropical coast-belt of Natal, but as we go further inland towards the plateaux both forms occur and every intergrade between them, until finally T. achine predominates. T. laura, from Central East Africa, is a variation of T. gavisa, in which the inner marginal black bars are very faint, or even absent; T. carleri, founded on a single female from Accra, being evidently the same form, of which I have seen every gradation through T. helle to antevippe (Boisd.). The tendency of several species of Teracolus on approaching the equatorial belt to lose their discal black markings is very curious and interesting. The only noteworthy distinction in T.fumidus, Swinh., from the Transvaal, is the trace of a transverse black bar on upperside of hind wings, a very variable character, not unfrequently appearing more or less faintly in specimens of T. achine, but never well developed. 63. TERACOLUS LAIS. Teracolus lais, Butler, Proc. Zool. Soc. p. 145 (1876). This is a distinct little species of the T. achine group from S.W. Africa, and may be distinguished from its allies by the small, very oblique, orange, apical patch, which has a distinct border of black along its inner edge. I have only seen dry-season specimens. |
