KELLOGG: SCLKRITES OF THE HEAD. 57 



pieces, or as flexible tube-lilce processes, as in Triptogon iiiodcsta (see 

 mx in fig. 7, Plate IF). 



Labium. 



The labium of archippus is a fixed, semi-membranous sclerite, trian- 

 gular in outline, with its apex projecting forward and joining the 

 maxillar proboscis at its origin (see //// in fig. 8, Plate 11). This inti- 

 mate union of the labium and maxillae is manifest in all of the few 

 lepidopterous heads I have examined. The well-known labial palpi 

 arise from the base of the triangular labium (see /. /. in fig. 8, Plate 

 11). The labium largely forms the floor of the head, and while not at 

 all uniform in outline among lepidoptera, well retains its general char- 

 acter of a fixed, more or less membranous sclerite (see hn in fig. 7, 

 Plate II, Triptogon niodesta; also //// in fig. 13, Plate II, Catocala sp.). 



The drawings for the plate accompanying this paper were made by 

 Miss Mary Wellman, to whom I am indebted for critical assistance. 



