COLIAS. 63 



( Vida Cracca\ Bird's-foot Trefoil (Lotus corniculatus], 

 Tuberous Bitter Vetch (Lathy rus macrorhizus), and Hop 

 Trefoil (Trifolium procumbens)^ seldom exceeds fin. in 

 length. It is nearly cylindrical, just tapering a little 

 towards the two extremities. The segments are divided 

 transversely into six sections, and the surface is covered 

 with short whitish hairs. The ground-colour is green, 

 and the anterior part of the body covered with tiny 

 black dots. The medio-dorsal line is dark green, 

 followed on each side by yellowish-green ; then comes 

 a dark green line followed by the spiracular line, which 

 is bright yellow. The ventral surface is green, and so 

 are the legs and claspers. 



The pupa (Fig. 51), which is fastened by the tail and 

 girt, is sharply pointed, especially at the anterior extremity. 

 The ground-colour is a beautiful green, which has a 

 yellowish tinge towards the anal extremity. There is a 

 pink stripe down each side, and the wing-cases are 

 bordered and veined with the same colour. 



The ground-colour of the imago (Figs. 48 and 49) is 

 pure white, the only markings being a squarish black 

 spot on the upper surface, at the tip of the fore-wings, 

 and a tinge of black at their base. On the under- 

 surface (Fig 49) there is in places a sprinkling of black 

 scales, and a tinge of yellow,, the latter especially at the 

 tip and base of the fore-wings. In the female the spot 

 at the tip of the fore-wings is often absent, or nearly so. 



Colias, BoisduvaL 



The genus Colias (containing the Clouded Yellows), 

 is, as far as British species are concerned, a very distinct 

 one. The ground-colour of the imago is white, yellow, 

 or orange, with a dark brown border along the outer 

 margin of all the wings. The fore-wings bear a central 



