THE SWALLOW-TAIL AND THE 'WHITES' 151 



The Clouded Yellow (Colitis Ediisd) 



Not oiily are this and the hist species simihxiiy named, but a 

 glance at the figures will show that they much resemble each other 

 in appearance ; and we shall also learn presently that in their habits 

 and life history they have much in common. 



The male Edusa is shown on Plate II (hg. 3), and when we 

 compare it with its relative on the opposite side, we are at once struck 

 with the superior richness of the brilliant orange or satfron of the 

 ground colour. The black border of both fore and hind wings is also 

 denser, wider, and more esteusi\e. The whole of the yellow area 

 of the hind wings is dusted more or less with black scales, with the 

 exception of a round central spot of deep orange, corresponding with 

 the orange spots on the hind wings of Hyalc. 



The female, which is shown in the accompanying woodcut, is 

 generally larger than the mile, and is further distinguished by the 

 \erv pale yellow spots 



\ 



tliat break the black 

 border of both pairs of 

 wings. 



Edusa fiu'ther resem- 

 bles Hijnle in the reddish 

 colour of the antennae ; 

 and, in both the species, 

 the red legs form a 

 pleasing contrast with the 

 yellow furry surface of the 

 under side of the thorax. 



There is a variety of the female of this butterfly, in which the 

 ground colour is a very ■pale yellow, almost white. The hind wings 

 are more thickly dusted with black scales than in the normal insect, 

 and the orange spots of these wings show up much more conspicu- 

 ously from the contrast with their surroundings. 



It is usual to applj' distinct names to constant varieties of species 

 — names that are to be added to the ordinary title. In this particu- 

 lar case the distinguishing name is Helice, so that we should speak 

 of tlie variety of Edusa above mentioned as : 



Colias Edusa, var. Helice 



Like Hijale, Edusa is particiilarly capricious in its appearance. 

 In certain summers it absolutely s^\■arms in favourite localities, 



Fig. Gfi. — The Clouded Yellow — Female. 



