42 BKITISH LEPIDOPTEKA. 



considers may be either " a mere concession to the mechanical condi- 

 tion of the process of pupation, or due to the larval pigment still 

 lingering unchanged in the pupal hypodermic cells." The pupal 

 sexual organs are, in the female, associated with the 8th (anterior 

 openings) and with the 9th or 10th (posterior openings) abdominal 

 segments ; in the male, the sexual organs appear to be placed one on 

 each side of the middle ventral line of the 9th abdominal segment. 



Lying ventrally along the costal edge of the fore-wings are the 

 pupal antennas, often distinctly segmented, and, in the Heterocerous 

 pupa, often with two long basal hairs on either side of the head ; whilst 

 within these medially are the three pairs of legs (rarely more than 

 two pairs visible), and quite centrally is a double ribbon of varying 

 length, the pupal tongue or maxillae, originating at the mouth and 

 varying greatly in length in the different superfamilies. The mouth- 

 parts consist theoretically (and actually, although all the parts are 

 rarely to be made out especially in the obtect pupa) of the mandibles, 

 the labrum, the maxillae and maxillary (1st) palpi, the labium and 

 labial (2nd maxillary) palpi. At the base of the antennae are the eyes, 

 the glazed lunular portion of which is generally very conspicuous. 



The most important of the pupal organs, however, so far as they 

 yield distinct phylogenetic characters, are the mouth and head-parts, 

 and these will have to be considered more or less at length. The 

 Mandibles are, in most lepidopterous pupae, almost obsolete. They are, 

 however, in Eriocrania, of immense size proportionately to the insect, 

 and functionally active, being used, as Chapman has shown, by the 

 insect to free itself from its dense and tough cocoon. He describes them 

 as " great curved organs, proceeding first directly forwards, then, by a 

 sweep of a quarter of a circle becoming directed to the other side, and 

 crossing the jaw of that side, proceeding transversely till the extremity 

 projects rather beyond the margin of the opposite side of the pupa ; 

 the shaft is enlarged at either end — proximally with three projections 

 or knobs for articulation, at the other end into a large truncate knob, 

 the margins of whose flat extremity are armed with three or four 

 large teeth and many smaller ones, reminding one in appearance of, 

 as they certainly resemble in function, the fore-paws of a Gryllotalpa 

 or Cicad pupa. The inner margin of the shaft is armed by a row 

 of nine or ten teeth, flat, sharp, and leaflet-like." He further writes 

 (Trans. Ent. Soc. Lond., 1893, p. 256) : "The mandibles are most remark- 

 able in 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 corresponding imaginal 

 parts attached to them. Yet all this may be easily observed by anyone 

 who will get the necessary material — by no means difficult to do — and 

 watch it from 6 to 7 a.m." As an example of the pupa-libera, Chapman's 

 further notes on Eriocrania are interesting. He writes : " The pupa has 

 all its appendages apparently quite separate and unfused together in any 

 way, and the abdomen is thus not only unattached to the legs and wings, 

 but preserves freedom of movement in all its segments. The head 

 and thoracic segments are equally free to move on each other, and do 

 so, especially the head, during emergence, yet, when the pupa is 

 quiescent, i.e., removed from its cocoon some time before emergence, it 

 does not move these segments when irritated, but only the abdominal 

 ones . . . The only portions of the pupa- skin at all solid are the 



