56 KELI.OGC;: SCLKRITES OF THE HEAD. 



and //in fig. 12, Plate II). Nor can the pilifers be construed to be 

 the maxillary palpi, for in addition to the fact of their identity with 

 the labrum, the maxillary palpi when present in lepidoptera, are found 

 in specimens along with, but distinct from the pilifers. The palpi 

 arise also from the immovable basal portions of the maxillae (see mxp 

 and //in figs. 13 and 14, Plate II, Catocala sp.). There is in arch- 

 ippus and in lepidoptera generally, a very small triangular piece pro- 

 jecting forward from the labrum (see epx in fig. 11, Plate 11^). This 

 piece is called ejjipharynx in *Lang's discussion of tlie Antennata in 

 his Text-book of Comparative Anatomy. 



Mandibles. 



The mandibles are wanting in arcliip/^iis. They are present in an 

 aborted condition in many lepidoptera. The mandibles have been 

 discussed under "Labrum" aiitca. 



Maxillae. 



The characteristic, long, coiling, sucking tube of the lei)idoptera is 

 composed of the greatly extended, opposed terminal portions of the 

 maxillae. In addition there is a fi.ved basal portion of each maxilla, 

 which cannot be divided into cardo and stipes. In archippiis the 

 basal portion extends backwards and downwards partially bounding a 

 cavity lying between it and the labium (see vix-b in fig. 8, Plate II). 

 The basal portion is shining brown. The maxillary palpi when present 

 arise from this fixed basal portion as in Catocala sp. (see mxp and 

 mx-b. in figs. 13 and 14, Plate II). fBurgess refers to two minute 

 tubercular points on the proboscis of archippus and an appreciable 

 distance from its base as the remnants of the maxillary palpi. 

 This does not seem reasonable. For the proboscis is probably com- 

 posed of one or both of the terminal plates (galea, lacinia) of the 

 more generalized maxilla, and the fixed portion is probably composed 

 of one or both of the basal sclerites (stipes, cardo) of the more gen- 

 eralized maxilla. In generalized maxillae the palpi arise from the 

 stipes. I By homology we should expect to find the palpus in lepidop- 

 tera arising from the fixed basal portion, which, as above stated, is 

 precisely the condition that is presented in Catocala and in those 

 lower moths possessing distinct maxillary palpi. 



In archippus the proboscis is long and composed of parts of both 

 maxillae (see vix in figs. 8 and 11, Plate II). In some lepidoptera, 

 however, the maxillar extensions are distinct, either as stiff blade-like 



*Lang. Arnold. Text-book of Comparative Anatomy. (Trans. Bernard. ) 1891. London 



tBiirgess. Edw. hoc. cV. 



iStrietly, perhaps, the palpi arise from the palpu.s-bearer which joins the stipes. 



