79 



bb. Maxillae always extending to the caudal margin of the wings and 

 sometimes beyond; wings never adjacent on the meson. 



Hesperiidae. 

 aa. Proximo-lateral angles of the maxillae never extending laterad to the 

 eye-pieces, 

 b. Mesothoracic legs never extending cephalad to the eye-pieces. 

 c. Epicranial suture always present; head without projections; 

 exposed part of maxillae never as long as the wings. 



Lycaenidae. 



ec. Epicranial suture never present ; head always with prominent 



projections; exposed part of maxillae usually as long as the 



wings. 



d. Head with two prominent projections, one at each cephalo- 



lateral angle ; metathoracic wings visible in ventral view. 



Papilionidae. 

 dd. Head with a median projection ; metathoracic wings not 



visible in ventral view Pieridae. 



bb. Mesothoracic legs extending cephalad to the eye-pieces and for a 

 short distance between the sculptured eye-piece and the antenna. 



Nymphalidae. 



Family Megathymidae 



The Megathymidae, or giant skippers, are evidently the most gen- 

 eralized of the Papilionoidea although they differ but little from the 

 more generalized Hesperiidae, some doubt existing as to whether they 

 show enough difference to warrant their being considered as a dis- 

 tinct family. However, as only one pupa of this family has been seen 

 by the writer and as that had lost some of the face-parts so that a 

 complete description can not be given, no very definite stand can be 

 taken here as to its position in the superfamily. The members of the 

 superfamily Papilionoidea, as a general rule, possess but little free- 

 dom of motion in the free segments and these are rarely capable of 

 being telescoped. In the Megathymidae not only are the free seg- 

 ments capable of a great deal of motion and of being telescoped, but 

 there appears to be dorsal motion possible between the third and 

 fourth abdominal segments, and the seventh abdominal segment ap- 

 pears to possess freedom of motion in the male. The abdominal seg- 

 ments are of nearly equal length, and the eighth, ninth, and tenth are 

 distinctly segmented. These characters, however, appear to be re- 

 tained in such generalized Hesperiidae as the genera Calpodes and 

 Amblyscirtes, in which if all the above-mentioned segments do not re- 

 tain freedom of motion they have certainly but recently lost it. In 

 placing this family in the Papilionoidea it has been assumed that the 

 pupae possess lobes indicating the presence of pilifers, but these parts 



