4 DONALDSON BODINE. 



and the pectinations, where they exist, arising from the ventral sur- 

 face. Some exceptions to the last clause will be noted later. This 

 description of the normal position and Fig. 26, representing the de- 

 nuded head and its appendages of Sphiiu- cher.'^is, will make clear 

 the application of the terms of position and direction employed in 

 the following pages. The natural position varies greatly in different 

 species. In some the antennae are directed nearly cei)halad ; in 

 others, almost as nearly caudad ; and all the possible positions be- 

 tween these extremes may be assumed. As the antenna^ are true 

 appendages, however, the general rule for the normal })osition of 

 appendages should obtain in all cases. 



MORPHOLOGY. 



The antenme belong to the pre-oral somite, and are usually the 

 most conspicuous pair of appendages of the head. They are slender, 

 segmented organs, and are inserted symmetrically, one on each side 

 of the meson, on the dorso-cephalic surface between or cephalad of 

 the compound eyes. In the Papilionina and Hesperiina, according 

 to Mr. Scudder,* and so far as I have observed, in the other Lepi- 

 doptera, the antenniie are inserted at the ends of the suture between 

 the epicranium and the clypeus, see Fig. 26. Kolbef says that, " In 

 the Diptera, Lepidoptera and Trichoptera, whose mouth-parts are 

 stunted, absent, or transformed into sucking organs, the antennae are 

 l)rought very near each other, while in the biting insects they usually 

 are sej)arated from each other." Mlcropteryx, one of the Jugatse, 

 which has retained its mouth-})arts slightly modified, has its an- 

 tennae inserted (|iiite far cephalad and relatively far apart; thus 

 it offers a peculiar confirmation of the generalization of Kolbe. It 

 would seem that, since the change in function of the mouth-parts 

 has not yet become complete, as indicated by the presence of those 

 organs in a condition less modified than in the other Lepidoptera, 

 the migration of the bases of the antennae has not progressed so far 

 as elsewhere in the order. The insertions here are at the ends of 

 the clypeal suture, but the sutui'e itself is strongly curved with the 

 ends bent cephalad. 



The proximal segment of the antenna is the largest and is termed 



* The Butterflies of the Eastern United States and Canada, in three Vols., by 

 S. H. Scudder, Cambridge, 18H9, vol. i. p. 37. 



t Einfnhnuifi in die Kenntnis der Insekten, von H. J. Koll)e. Berlin, 1(S93, 

 p. 179. 



