218 Canadian Butterjlies. 



The last family dilTers from all the others in the habit of the cater- 

 pillars rolling lip leaves, within which they undergo their trans- 

 formations. 



FAMILY I. PAPILIONID^, LEACH. 



This family consists of some of the most gigantic species of 

 Butterflies, distinguished by the perfectly ambulatory structure of 

 all the six legs, the anterior pair not being more or less rudimen- 

 tal ; the hind tibiae have only a single pair of spurs at the tip; the 

 tarsal ungues or claws are distinct and exposed, single or bifid ; 

 the antennse ai-e never hooked at the tip, the club being distinct, 

 but variable in form ; the palpi are variable, but the third joint is 

 never suddenly slenderer than the rest and naked ; the discoidal 

 or central cell of the hind wings is always closed behind by a 

 nervure ; the abdomen is short, slender, and often laterally com- 

 pre sed ; the proboscis short, or moderately long. The Caterpil- 

 lars are elongated, nearly cylindrical, but are frequently thickened 

 or shortened, and are either smooth or pubescent, rarely spinous ; 

 the Chrysalides are attached, not only by the ordinary anal hooks, 

 but also by a girth round the middle of the body. In one genus 

 (Parnassius) it is, however, inclosed in a rough cocoon. Almost 

 all the Butterflies of this family are powei-ful fliers, and it fre- 

 quently requires a good chase to capture specimens of some of the 

 species. 



This numerous family is divided into two verj- distinct sub-fami- 

 lies — Papilionidi and Pieridi — both of which are well represented 

 in this country. 



SUB-FAMILY I. PAPILIONIDI. STEPHENS. 



Anal edge of the hind wings concave, or cut out to receive the 

 abdomen ; the anterior tibiae have a spur in the middle ; the tar- 

 sal ungues or claws are simple ; they are furnished with very 

 powerful muscles at the base of the wings, which are very large 

 and their flight rapid. The Caterpillars are slow, cylindrical, 

 thickened, and never villose or hairy, but a few are armed with 

 spines. They are always furnished with two fleshy retractile ten- 

 tacles in the form of a Y, issuing from a common tubercle, upon 

 the back of the segment succeeding the head, which the insect 

 throws out when alarmed, emitting at the same time an acrid 

 liquid with a disagreeable odour. This curious organ is supposed 

 to be intended us a weapon of defence against Ichneumons and 

 other parasites, to the attacks of which they are very subject. 



