PAPILIONID.E 



241 



The next group are day-flying, butterflies, etc., and have 

 a difl'erent form of antennae. The skippers are somewhat 

 intermediate. Their antennae are slender and run out. 

 sometimes into a hook, or end in a thread-hke structure. 

 The butterflies ha\'e a thickening at the tip of the antennae. 

 Butterflies are strictl\' diurnal and are contained within 

 four or five distinct families. Hesperidae are intermediate 

 not only in these antennae but also in the wings. In the 



Fig. 185. — Cecropia moth, larva; natural size. (Photo. Ohio Exp. Sta.) 



butterflies the wings are folded up vertically over the back. 

 In Hesperidae they are about half and half. Some fly at 

 twilight — the yucca-borer — others in the daytime. 



Superfamily Pajnlionidce includes the swallow-tailed 

 family. There is a tail-like appendage on the hindwings, 

 which varies considerably in different species. The larvae 

 are most of them characterized by the presence of peculiar 

 fleshy organs which are projected from the segment behind 

 16 



