68 BUTTERFLIES 



rows of yellow spots along the margins of the front wing. 

 These spots are present also on the hind wing where they 

 are almost changed to blue because overlaid with a gen- 

 eral cloudiness of this color. On the under surface of the 

 hind wings there are two rows of orange-brown spots, the 

 inner row being nearly crescent-shaped and the outer row 

 oblong. In the living insect the tail projections on the 

 hind wings are usually twisted into a vertical plane at 

 right angles to the plane of the wings. 



The caterpillars of this species feed upon the leaves of 

 sassafras and spice bush. The distribution of the but- 

 terfly appears to be closely related to the distribution of 

 these plants. 



As is the case with so many of our Swallowtail butter- 

 flies, the Green-clouded Swallowtail passes through the 

 winter in the chrysalis stage. Late in spring the butter- 

 flies emerge and soon afterward lay their eggs singly upon 

 the leaves of sassafras or spice bush. The eggs soon hatch 

 into lead-colored caterpillars, largely covered with spiny 

 warts. Each caterpillar cleverly makes a protecting 

 nest by eating out a narrow strip in the leaf which frees a 

 flap along the margin that is turned back upon the leaf, 

 making a case in which the larva lives. It spins a silken 

 carpet on one side of the case and rests upon this car- 

 pet when at home. During its feeding periods it goes 

 outside and eats the tissues of the other parts of the same 

 leaf. It continues to occupy this first nest for a week or 

 more b}^ which time the rest of the leaf is likely to be 

 pretty well consumed. 



Having passed the first moult and thus become larger 

 and having practically eaten itself out of its first house 

 and home the caterpillar now crawls to a larger leaf where 



