156 PROCEEDINGS ENTOMOLOGICAL SOCIETY 



are utilized in locomotion, when the pupa digs up through the 

 earth. The legs are rather feeble and immovable and are not 

 used for this purpose as has been asserted. 1 



The pupal skin is very thin and transparent, so that the imagi- 

 nal hairs and scales, as well as the eyes and ocelli can be plainly 

 seen through it. The only part of the pupa which is strongly 

 chitinized, besides the large mandibles, is the supporting mouth- 

 frame (figs. 14-18) formed by epistoma, pleurostoma and hypos- 

 toma. 



From the front projects downwardly a large, peculiar, beak- 

 like, soft process, reaching above and beyond the base of the 

 labrum. On the upper part of the front are two pairs of long, 

 curved, stiff hairs, the same which persist on the head of most 

 Lepidopterous pupae (fig. 16). 



The eyes are large. The antennae are free throughout their 

 entire length and run in a broad curve over the base of the wings 

 and rest on the costal edge of the wings, reaching nearly to their 

 tips. The first joint is large and elongate, four times as long as 

 the succeeding joints. The tufts of hairs on the imaginal joints 

 are plainly visible through the pupal sheath. 



The labrum is large, subquadrate, with incurved front margin. 

 It is rather firm and bears six pairs of long stiff bristles. 



The most conspicuous of the mouth parts are the very long, 

 stout, curved, armlike mandibles (fig. 15). These are strongly 

 chitinized and dark brown in color. Their fossa and condylus 

 are strongly developed and firmly jointed to the mouth frame. 

 Their inner edge is sharply serrated nearly to the end and the 

 apex is broadened out into a formidable club, which is abruptly 

 cut off with a flattened, somewhat hollow end, the edges of which 

 are armed with several strong teeth. They are capable of a strong- 

 outward swinging movement, which is used to tear the tough 

 cocoon and afterwards to dig up through the soil. 



The mandibles are moved by strong muscles (fig. 18), identical 

 with the abductor and adductor mandibulse found in insects with 

 biting mouthparts, and the minute imaginal mandibles can be 

 found within their base by dissection (fig. 14). In this connection 

 we refer to Chapman's peculiar statement in his otherwise very 

 lucid account of an "Eriocranid" pupa. 2 



1 Sharp, in his textbook, p. 327, 1909. 



'That a Lepidopterous pupa should have jaws is remarkable enough; 

 that they should be of such immense size proportionately to the insect and 

 should be functionally active seems at first sight incredible; but the still 

 more remarkable fact remains, that active and powerful as they are, there 

 are no visible means of working them, as they are pupal structures, used 

 only immediately before the emergence of the imago and have no corre- 

 sponding imaginal parts attached to them. 



"The whole question, how these jaws are worked, will form an intorestin-j; 



