APORIA. 39 



have at times supplied it, at least singly, though probably 

 most of those that turn up now and again in unexpected 

 places have escaped from captivity. Its chief home now 

 is in the Fens about Cambridge, Huntingdon, and Nor- 

 folk, two favourite localities being Ranworth Fen and 

 Wicken Fen, but it is there less plentiful than formerly, 

 and it is to be feared that, as the drainage of the Fens 

 goes on, it will share the fate of the Large Copper, and 

 become extinct as far as our islands are concerned. 



FIG 16. PAPILIO PODALIRIUS. 



Though it is, of course, a good thing that the Fens 

 should be drained and cultivated, yet we could not help 

 feeling regret should this remove from our list such an 

 exquisite butterfly as Papilio machaon. 



Aporia, Hiibner. 



Aporia, the next genus, contains but one British 

 species, crat&gi (Fig. 17), and even this has some- 



