's RIJKS MUSEUM VAN NATUURLIJKE HISTORIE — LEIDEN. 243 



colour on the under side of the hind wings, the ocellus on the upper 

 side of the fore wings and, last not least, by the claps (valvae) and the 

 uncus in the genitalia of the male specimens. Messrs. Elwes and Edwards 

 have given figures on plate 1 in the cited Transactions. 



Mr. Piepers „is not unable to admit the separate wet- season race 

 marshalli Butl. of Fruhstorfer, at least as far as Java is concerned." As 

 far as I can determine, the name marshalli Butl. of Fruhstorfer indicates 

 the dry -season form (Seitz, p. 289). The eleven specimens of both sexes, 

 taken at the height of the dry season at Tjandi by Mr. Edw. Jacobson, 

 must belong, concerning the opinion of Mr. Piepers, to the form balclus 

 F. These eleven specimens belong to the species horsfieldii Elw. & Edw. 

 and not to the species marshalli Elw. & Edw. or balclus Piepers and 

 Fruhstorfer. The figures 37 a — b and 38 a — d on plate 16 in „The Rho- 

 palocera of Java" are showing distinctly the morphological differences 

 between the two species, while, in the table of species on page 25 of the 

 cited Transactions, Messrs. Elwes and Edwards have indicated the anato- 

 mical differences. It is a pity, that the latter authors have not figured 

 the valvae of their horsfieldii. Therefore I have sketched here the valva 



(V.) and the uncus (U.) of marshalli (1,3) and horsfieldii (2,3) Elw. & 

 Edw. De Mcéville's investigation of the seasonal dimorphism of marshalli 

 Elw. & Edw. proves conclusively that the dry -season form has the 

 ocelli on the under side of the hind wing very much smaller than 

 the wet- season form , but he has not written that between the two 

 seasonal forms distinct differences in the shape of the wings and in the 

 genitalia exist. As far as I know such a fact would be unknown. On 



