118 Dr. F. A. Dixey on the phylogenetic 



a mere projection on the summit of III. 8, the filling up 

 of the valley between II. 7 and IF. 7, and (in P. cardui 

 and myrinna) the disappearance or melting into IV. 8 of 

 11. 8 ; to which must be added in P. callirrhoe the gradual 

 overspreading of the wings by a dark ground colour 

 advancing from the base, this feature reaching its 

 highest development in P. atalaiita and P. fionerilla. 



If the identification of the spots already given be 

 correct, they can of course be easily found in any ordi- 

 nary Argynnis. The greatest doubt exists with reference 

 to II.' 7 and 11. ' 8, which would seem to be usually 

 absent. A spot corresponding to the former may, how- 

 ever, sometimes be seen in A. lathonia and A. adippe (as 

 in specimens in the Hope Collection), while one in the 

 position of the latter occurs normally in A. lathoyiia and 

 A. niphe, and not infrequently in A. childreni, A. idalia, 

 and other species of the genus. The present series is 

 thus seen to constitute no exception to our general rule; 

 and to be traceable as to its posterior portion with 

 certainty, though as to its anterior with some doubt, 

 from its earliest beginnings in such a form as A. diana 

 $ , where it is hardly to be distinguished from the 

 general ground colour, through the more specialised 

 Argynnids to the highly modified form it assumes in 

 Araschnia, Pyrameis, Grapta, and Vanessa, the difficulty 

 of identification in the latter genera arising, as in the 

 former cases, partly from the suppression of some of 

 the spots, and partly from the fusion of spots belonging 

 to the same or different series. 



6. Tlie markings within the discoidal cell. — The last 

 series of markings that calls for notice is that which 

 occupies the discoidal cell in fore and hind wings, dis- 

 tinguished collectively as series I. These in the fore 

 wing consist in their simplest form of five transverse 

 marks, I. 1 being a small black patch in the angle 

 between the subcostal and median nervures (fig. 4), 

 I. 2 and 3 being united into a more or less complete 

 ring (under side of P. atalanta, both sides of A. adippe 

 and some other Argynnids, figs. 4, 42). It is probably 

 the latter of these two marks that forms the innermost 

 of the black costal patches in V. polychloros, V. urticcB, 

 and V. io (figs. 1, 2, I., cf. figs. 42, 43). I. 4 appears in 

 most Argynnids as a curved band with its convexity out- 

 wards ; in 1\ cardui as a process from the summit of IL' 7, 



