NOVITATES ZOOLOGICAE XXIl. 1915. 85 



I accept as thetis all those forms whose male appendages are, if iKit quite 

 identical, still very nearly so, and differ abundantly from those of the forms I 

 regard as distinct species. 



With this definition, thetis has a very wide range, and a good deal of variety 

 in several respects; and until the evidence of the genitalia appears, these forms 

 seem in some cases to be more entitled to be accepted as distinct species than 

 others that really are so, but have been by various authorities lumped with 

 tlietis. 



C. thetis has usually a fairly broad dark border and large dark tip, whilst 

 phaeclrus has usually a comparatively very narrow border and tip, and the red 

 colour is paler and yellower, or if not so in the field more readily becomes so in 

 the cabinet. 



On the underside both are given to be pure white with so little black marking 

 that not much can be made of it. In better-marked specimens, however, there 

 is a very marked distinction : in phaedrm the postdiscal line on both wings is 

 fairly straight and regular, whilst in thetis it has a separate curve in each space, 

 and varies in distance from the base, as it does in many other species ; for 

 comparison with phaeclrus it may be sufficient to note that the line on each side of 

 vein 5 of hindwing is markedly advanced to the margin. 



In Iris xii. p. 247 (1899), Ribbe has some remarks on solita of Butler and 

 thetis generally, that one must agree with. He says he has a specimen from 

 Neu Pommern and one from Bongainvillo wliich he believes to be solita. He says 

 the Curetis from the neighbouring regions are so much alike, that it is extremely 

 difficult to distinguish between them. Dr. Pagenstecher, he says, desires to lump, 

 but he would rather separate them ; as for instance thetis Drury has females 

 with white patches, barsine Felder with golden, and solita with nearly obsolete 

 golden patches. 



When one has examined the appendages of a number of these forms, much 

 the same considerations hold. All these species (that is all I regard as being 

 in this group), which I have examined, have appendages that agree very closely 

 with those of thetis. 



They all have the shuttle piece in the aedeagus of much the same form. 

 The chief differences are in the harpes. lu what I assume to be thetis (Drury) 

 the harpe has at about 0i5 mm. from its extremity a projection or flap on the 

 margin next the valve, giving it in fact two extremities, one direct, one lateral. 

 In the forms of thetis from these islands, there seems to be considerable variation 

 in these two extremities, which gradually approach each other, culminating in 

 a broad and thickened end such as characterises ribhei. 



It must be largely a matter of personal equation how many of these forms 

 are held distinct and how many are geographical races of one species. Whilst the 

 data are in so many directions defective we cannot answer the question which 

 are distinct species ? but only the more vague one, which shall we assume to be 

 distinct species? In the Solomon Islands we have the females with brown, not 

 white patches ; we may assume this to be a good specific character, or minimise it 

 as a kind of dimorphism. In ribbei, that seems distinct, the ? ? have all the 

 appearance of fine large thetis. I should incline myself to call them all 

 geographical races, and to expect to find a slightly different race on fairly 

 separated islands or groups of islands, and with a sufficient series of such races 

 to find a large amount of grading between the different forms. No doubt each 



