376 



THE STUDY OF INSECTS. 



thorax. 



These have been termed osinatcria (os-ma-te'ria), 



and are supposed to be 

 organs of defence ; for 

 they exhale when pushed 

 out an odor which in some 

 species is exceedingly dis- 

 agreeable. 



The chrysalids are 

 thickened in the middle 

 and taper considerably at 

 each end ; they are more 

 or less angulated, and have 

 certain parts excessively 

 produced ; they are sus- 

 pended by the tail and by 

 a loose girth around the 

 middle. 



This family includes 

 two well-marked subfami- 

 lies, which are distin- 

 guished as follows : 



FIG. 456. Wings cf Papilio polyxenes. 



A. Hind wings with a tail- 

 like prolongation ; ground- 

 color of wings black ; radius 

 of fore wings five-branched ; the base of vein VIII of fore wings 

 preserved as a spur-like branch of vein VII (Fig. 456). p. 376 



PAPILIONIN^;. 



AA. Hind wings without tail-like prolongation ; ground color of 

 wings white ; radius of fore wings four-branched ; vein VIII of fore 

 wings wanting, p. 380 PARNASSIIN/E 



Subfamily PAPlLlONlNyE (Pa-pil-i-o-ni'nae). 

 The Swallow-tails. 



These magnificent butterflies are easily recognized by 

 their large size and the tail-like prolongations of the hind 

 wings. The ground color of the wings is black, which is 



