234 LEPIDOPTERA. 



and the femoia, tiljue iind tarsi, slender and verj'- equal in 

 length. There are umiuiII^' two tiljial spurs. The tarsus is 

 five-jointed, the terminal joint ending in two slender claws. 



The scales co^'cring the bod}' of Lcpidoptera are simply 

 modified hairs. In studying the wing of the Cecropia moth, 

 we find the hairs of the bod}^ and base of the wing graduallj^ 

 passing into the forms represented in Fig. IGG. The}- are 

 attached to the wings and laid partially o^er one another like 

 the tiles on a roof (Fig. 1G7). They are inserted in somewhat 

 regular lines, though, as seen in the figure, these lines are often 

 irregular, as shown by the line of scars where the scales have 

 been removed. The scales are beautifully ornamented with mi- 

 croscopic lines. "We find, on removing the scales, that the 

 head consists of three well-marked pieces,* i. e. the occiput 

 or basal piece which lies behind the ocelli ; the epicranium, 

 lying behind the insertion of the antennae, and carrying the eyes 

 and ocelli, and the cl^'peus, which constitutes the front of the 

 head. The latter piece is larger than in all other insects, its 

 size being distinctive of the Lepidoptera. There is a general 

 form of this piece for each famil}-, and it aflbrds excellent 

 characters in the different genera, especially among the butter- 

 flies (as Mr. L. Trouvelot has shown us in a series of drawings 

 made by him), and the Zygcenidce and Bomhycidce. It is 

 largest, and most perfectly shield-shaped, in the Attach In the 

 PhalcBnidcG, it is smaller, and square ; and in the Tine idee 

 it is smaller still, while the occiput and epicranium are 

 larger. 



The labrum is remarkably small and often concealed b}' the 

 overhanging ctypeus. The labium is small, short, triangular, 

 and the mentum is nearly obsolete. The lingua is obsolete, its 

 place being supplied b}^ the tongue-like maxillte. The labial 

 palpi are feebly developed, sometimes rudimentarj', and consist 



* Pig. 108. A, head of Ctenucha Virginica denuded; oc, occiput; ec, epicranium, 

 with the two ocelli, o, and the base of the antenna;, at; e, eye; c, clypeiis; i, la- 

 brum; m, niaijdible: ma;, tongue, or maxillre, with the end split apart; B, rudimen- 

 tary maxilla of Aotias Luna, with its single-jointed rudimentar\' palpus, sho\\ ing 

 the mode of attachment to the base of the niaxdla; C, two-jointed, rudimentary 

 labial palpus of A. Luna; D, the same, single jointed, of Platysamia Cecropia. 



Figs. 169, 170. Head of amoth in relation to the prothorax (1). Fig. 171, A, C, side 

 view and (C) front tIcw of the head of a moth ; a, antenna ; h, eye ; d, the '• front ; " 

 e, orbit of the eye; f, ocellus; g, maxilla situated between h, the three-jointed la- 

 bial palpi ; i, the maxillary palpus, sometimes very large and three-jointed. 



