OUTLINES OF ENTOMOLOGY. 79 



seeming absence of the front pair of legs, and, to a certain extent, in 

 the coloring. 



Butterflies have been classified and re-classified in various ways, 

 by diflFerent naturalists, each system based on some excellent ideas, but 

 all more or less defective. The simplest arrangement is that by which 

 they are all grouped into four comprehensive families, all of which 

 are numerously represented in all parts of the United States. These 

 families are : the Swallow-tails and their allies (Papilionid^), the 

 Browns and Silver-spots (Xymphalid^), the Little Blues and Coppers 

 (LyC-^nid^,) and the Skippers (Hesperid^). 



The Swallow-tails (genus FapilioJ are so called from the narrow 

 lobes or tabs into which the outer edges of the lower wings are pro- 

 longed. Among these we find the largest and some of the most beau- 

 tiful of our native species. They are mostly of dark colors — black or 

 rich brown, ornamented on the wings and body with spots and streaks 

 of bright yellow and orange, with shadings or lustrous reflections of 

 blue or green. The club of the antennae is rather small ; the tibiiie of 

 the hind legs have a single pair of spurs, and those of the fore legs at 

 the base a sort of flap covered with long hairs. All the species in the 

 family have six equally developed legs. ( See Fig. 32.) 



The larvae are, with one or two exceptions, smooth, cylindrical cat- 

 erpillars, often gaily striped or ornamented with eye-like spots (see 

 Fig. --^), and possess a distinguishing character in a V-shaped scent 

 organ fosmateriumj of an orange color, which can be protruded at will 

 and emits a disagreeable odor. It is used to frighten away parasitic 

 enemies. This appendage is peculiar to the larva; of the true Papilios, 

 and when the insect is quiet, is completely retracted under the edge of 

 the segment next the head. The larva of Papilio asterias feeds on the 

 foliage of carrots, parsley, caraway and other umbeliferous plants. 

 The chrysalis is marked in wood brown and white, and has the form 

 represented in Fig. 32. The butterfly is black, with bluish shadings, 

 and is ornamented with several rows of bright yellow dots near the 

 outer edges of the wings. The Turnus hviii^T^j (Papilio turnus, Linn.) 

 is one of the largest and commonest species, expanding over four 

 inches. It differs from all its congeners in having the ground color of 

 the wings bright yellow, but crossed by broad dashes and streaks of 

 black, and with a black border in which are set lunate yellow spots. 

 The larva is deep green, and about one and one-half inches in length 

 deep when full grown. The front edge of the second joint and a part of 

 the fifth joint are yellow, and on each side of the fourth joint are a 

 couple of small purple spots. The chrysalis is in various shades of 

 e— 6 



