BUTTERFLIES OF THE DISTRICT OF COLUMBIA 199 



wings from 39 mm. to 48 mm. in length. The hair on the front of 

 the head is short and does not form a conspicuous tuft. In the fore 

 wings the outer and lower margins make an obtuse angle with each 

 other. The hind wings are much less deeply scalloped than in the 

 early-spring form and the tails are much longer. The dark markings 

 are extended and the outer half of the hind wings is mostly or wholly 

 black. The pale stripe crossing the cell included in the second dark 

 band on the fore wings is absent, or only faintly indicated. There 

 is a conspicuous pale stripe along the abdominal fold. The first and 

 last of the submarginal yellow lunules on the hind wings are usually 

 much reduced or vestigial. The red spot at the anal angle is merely 

 the inner half of the corresponding spot in the spring form, with 

 sometimes (in some males) a small isolated red spot beyond it. The 

 white margin of the tails extends almost to the base. This form flies 

 until the end of the season. The largest individuals are found from 

 the latter part of July until October. 



It may be pointed out that in all the other swallowtails, with the 

 single exception of the parsnip swallowtail {Papilio polyxenes), the 

 earliest spring individuals are much smaller than those emerging 

 later, Avhich approach, or even equal, summer individuals in size, 

 while in the yellow clover {Oolim philodice), the cabbage butterfly 

 {Piens rapae)^ and the common blue {Lycaenopsis argiol^s pseudar- 

 giolus) late-spring individuals resemble those of the summer broods, 

 and not those emerging earlier, in size and color. 



Caterpillar. — The full-grown caterpillar is about 2 inches in length 

 and is broadest at the third segment behind the head, thence tapering 

 to the hinder end. It is pea green with a broad black transverse band 

 on the dividing line between the third and fourth segments and very 

 narrow dark transverse lines or rows of spots on all the segments. 

 There are no eye spots in advance of the dark band. 



The caterpillar feeds upon the papaw {Asmiina triloha). 



Chrysalis. — The chrysalis is smooth, short and stout, either bright 

 green or brown in color. The abdomen is not expanded laterally, 

 and the ventral surface is nearly straight. 



Remarks. — In 1929 and 1930 this butterfly, so far as I have been 

 able to learn, was not to be found anywhere in the District area after 

 the first week in May, but in 1931 it was more numerous than it 

 had been for many years, occurring in the vicinitj^ of Cabin John 

 throughout the summer. 



Though I have found many of the eggs of this species on papaws 

 at Cabin John in spring, I have never seen the caterpillars here. 



NOTE 



In addition to the species of Papilioninae considered in the preced- 

 ing pages, Papilio palamedes (see p. 252), may possibly be found 

 here. 



66544—32 14 



