THE EXTERNAL MORPHOLOGY OF THE LEPIDOPTEROUS PUPA. 43 



labrum, which carries six long hairs on either side, the jaws, and an 

 oval hoop to which they are articulated." The labeum of the Erio- 

 craniid pupa forms a brown knob, as we have just noted, and bears six long 

 bristles on either side. It is a large, solid piece, contains no imaginal 

 structure, but doubtless serves, by its hairs, as a tactile organ during 

 the exit of the pupa, and, by its solidity, assists the action of the jaws, 

 probably both as a solid base to act from and as attaching the parts to 

 the imago. Packard notes that the labrum of the Taleporiid pupa 

 forms a thick prominent lip. 



The maxilla are exceedingly well-developed in many lepidopterous 

 pupae, forming a long double ribbon extending down the medio-ventral 

 line, often passing under the apices of the wings and projecting beyond 

 to some distance, sometimes to the 5th abdominal segment. In cer- 

 tain Sphingids, with enormously developed imaginal tongues, a special 

 arrangement takes place, the pupal tongue being folded towards the 

 base, whilst in the genus Cucallia it stands somewhat away from the 

 ventral surface and is bent considerably under towards the tip. 

 The maxillae are, generally speaking, more or less ill-developed 

 in the more generalised families ; in the Eriocraniids, they are very 

 inconspicuous, and in the Cochlidids also " they are small, but 

 are prolonged outwards, and after passing through a narrow neck, 

 terminate in a (sometimes rather twisted) club between the eyes, 

 antennae and legs. This represents the maxillary palpus which 

 nowhere in Macros has any such development ' ' (Chapman) . In the 

 true Tineids the maxillae are noticeably small, as also in the direct 

 Tineid offshoots. 



The maxillary palpi are absent in many lepidopterous pupae, espe- 

 cially in the more specialised superfamilies, although some pupae- 

 incompletae, Tischeria, Choreittes, &c, have no trace of them, and in 

 others, as FAaclmta, Bucculatrix, &c, they are very small. Strangely, 

 the pupae of those species of the generalised superfamilies that have 

 inconspicuous maxillae have often well-developed maxillary palpi. In 

 the Eriocraniids both are well -developed, the palpi being very large, 

 passing directly outwards transversely to the margin of the pupa, 

 afterwards returning to the central line, the returning portion ventral, 

 and, perhaps, a little posterior to the outward half ; they appear to be 

 quite free, but are not moved during pupal existence. The position is 

 really the same as in other Heterocerous pupae that possess these 

 organs, but in them, they are closed in by the neighbouring parts, 

 except the front of the terminal segments. In the Cossids there are 

 only small pupal maxillary palpi, and the lateral flap is not distinct. 

 The maxillary palpus is the structure which Chapman called (Trans. 

 Ent. Sac. Lond., 1893, p. 104) the " eye-collar." In the Adelids, it 

 consists of a narrow strip lying transversely immediately below the eye 

 and stretching from the maxillae to the antennae, and appears to come 

 from beneath the antennae. It also occurs in the Sesiids, but when 

 Chapman examined a pupa of Trochilium bewbeciforme, from which the 

 imago was ready to emerge, he found no corresponding imaginal part 

 in it, although he discovered that the " eye-collar " was really the case 

 of the maxillary palpus, and that the appearance, of coming, not from 

 the mouth, but from under the antennae, and passing inwards, was in 

 agreement with the actual fact, for the palpus, after leaving the 

 maxilla, passes backwards in the angle between the head and prothorax 



