significance of wiiKj -markings. 109 



4. The dark area between C and D. — Having traced C 

 and D throughout many of the species of the group, we 

 shall, of course, find it easy to identify the dark area 

 included between C and D in the same insects. 



On the upper surface of the fore wing in P. cardui and 

 P. atalanta, this dark area simply partakes of the 

 general black or dark brown of the ground colour of that 

 part of the wing, and shows no tendency to break up 

 into separate constituents. 



In V. io the same area is easily recognised as forming 

 the centre of the ocellus in the fore wing, and a part of 

 it is here suffused with the ruddy chestnut of the general 

 ground colour. 



In V. urtica: this area somewhat resembles in shape 

 the same area in V. io, but is sharply marked off from the 

 red ground colour. V. polychloros shows us the same 

 dark patch, in many cases breaking up into a chain of 

 spots which run parallel with the submarginal series IV. 

 and the hind border of the wing. Much the same 

 ai^pearance is presented throughout the genus Grapta, 

 but in Grapta c-aurcum we find the suggestion of a 

 breaking up of the area into two lateral constituents by 

 the inclusion of a patch of the ordinary ground colour 

 just internal to D a. This resolution is faintly indicated 

 on the under side of some of the species we have 

 already noticed by a paling of the ground colour towards 

 the middle of the patch. Turning now to the genus 

 Argijnnis, we find, as before, the same arrangement in a 

 more simple and intelligible form. The dark area is 

 completely resolved into dark spots, situated on the 

 ordinary ground colour, and falling into two series, an 

 inner and an outer. The outer series is clearly seen to 

 be the first part of a chain of eight spots, running right 

 across the wing to the inner border, generally parallel 

 with series IV., but with a decided inwards curve 

 opposite the middle of the hind border. This is the 

 series I have named III. It is, of course, one of the 

 most constant and characteristic features of the pattern 

 of the ordinary Argynnids. 



The inner constituent is a triangular or crescentic 

 patch, usually an obtuse-angled triangle, with its base at 

 the costa, and its apex pointing backwards and out- 

 wards. This I distinguish by the sign III', (fig, 31, 

 cf. 4, 27), It is generally large and well-marked in the 



