The Moths and Butterflies 
447 
butterflies are found in the United States. Combined with them in the 
family Papilionidae are two species of curious thinly scaled black- and red- 
spotted white butterflies called parnassians, which live exclusively in high 
Fig. 639. —Swallow-tailed butterflies, Papilio rutulus. (From life; one-half 
natural size.) 
altitudes in the Rocky and Sierra Nevada Mountains. Two more species 
are found in high latitudes on this continent, namely in Alaska. Parnas- 
sius smintheus (PI. V, Fig. 8; also Fig. 633) with four varieties is found 
in both the Colorado Rockies and Sierra Nevada, while P. clodius , a larger 
