90 BRITISH BUTTERFLIES. 



THE IAEGE TOETOISESHELL BUTTERFLY. 



(Vanessa Polychloros.) (Plate IX. fig. 1.) 

 THE beginner often has a slight difficulty in finding 

 a good and permanent distinction between this species 

 and the next (V. Urticce). At the first blush, the 

 superior size of this seems to be a sufficient mark, and 

 then the orange of the wings has usually a much 

 browner, or more tawny hue, than that of Urticce ; but 

 as I have seen specimens of Polyohloros absolutely 

 smaller than some very large Urticce's, and as the colour 

 of both occasionally varies, so that they approach each 

 other in this respect also, it is evident we must look for 

 some better mark of distinction ; and here is one. In 

 Polychloros, all the light markings between the black 

 spots on the upper edge of the front wing are yellow, 

 whereas in Urticce the outer one next the blue and black 

 border is pure pearly WHITE. The two other marks on 

 the front edge are yellow. Polychloros has also, near 

 the lower corner of the front wing, an extra black spot, 

 not found in Urticce. 



The blue spots on the border are in this species 

 almost confined to the hind wings. 



The caterpillar generally feeds on the elm, whence 

 the butterfly is occasionally called the " Elm Butterfly," 

 but it has also been found on the willow, and on the 

 white beam-tree. Mr. Boscher of Twickenham informs 

 me that the specimens he has bred from caterpillars fed 

 on the willow have been all far below the average size. 

 The caterpillar is thorny, and of a tawny colour, broadly 

 striped with black along each side. 



The chrysalis is of a dull flesh colour, with golden spots. 



The butterfly makes its appearance in July and August, 

 hybernated specimens being also frequently seen in the 

 spring, from March till May. 



In some places and seasons it is not rare, but is very 

 uncertain in its appearance, abounding most in the 

 southern districts, and being almost unknown in Scot- 

 land. It is fond of gardens and other frequented places 



