Papilio dardanus (^mcrope) lutd, Acrxa johnstoni. 285 



possessed by an interesting example, to be described below 

 (see p. 290), showing the origin o'i truphonius from triincni. 

 It is also possessed by two examples of the sub-species 

 mcrope $ f Idpipocoon in the National Collection, These 

 specimens, both from the west coast, are represented in 

 Plate XIX, Figs. 2 and 3. 



(/i) Prominence of suhnarginal pale spots in hind-iuing 

 of trimeni, etc. 



Another primitive feature usually characteristic of 

 trimeni is the large size and prominence of the sub- 

 marginal pale spots in the black border of the hind-wing. 

 These sjDots are of course persistent traces of the yellow 

 ground colour of the male and unmodified female enclosed 

 between the two black bands parallel with the hind-margin 

 of the hind-wing. The band of ground colour is widest and 

 most prominent between the root of the " tail " and the 

 '■' inner gap," as will be seen by a glance at Figs. 1-6 on 

 Plate XVII. Furthermore this especially prominent patch 

 is widest immediately on the inner side of the root of the 

 " tail," because it is here continuous with the ground 

 colour in the " inner gap " (Plate XVII, Figs. 1-5) or enters 

 the bay by which the closed gap is indicated (Fig. G). It 

 is precisely in this region, between the second and third 

 median nervules, that the pair of submarginal spots even 

 in the most specialized female forms often tend to be 

 largest and most conspicuous. This is well seen in the 

 ccnca, forms represented on Plate XVII, Figs. 8 and 11 ; 

 and in the hippocoon shown on Plate XIX, Figs. 2 and 8. 

 In the more primitive trimeni we expect to find and we 

 do find these tendencies more marked and accompanied 

 by a far higher degree of development of the whole series 

 of paired submarginal spots on the hind-wing. The special 

 size of the pair marking the position of the inner gap is well 

 seen in the tihullus trimeni represented on Plate XIX. Fig. 1, 

 and even better in the polytrophus trimeni of Plate XVIII, 

 Fig. 1. In this latter the two enlarged spots have fused into 

 a single and prominent patch. The development of the 

 series of submarginal spots in trimejii is however far better 

 seen in three specimens of this form of the sub-species 

 polytrophus in the Hope Department, — specimens which in 

 other respects were less instructive than that represented 

 on Plate XVIII, Fig 1. 



We can at once understand by the study of the examples 



