LACHNEIDES. 443 



the Lachneid pupa has but little freedom of movement within the cocoon, 

 being well attached to the cast larval skin, which in turn is usually 

 fastened to the inside of the cocoon. The cocoons of P. populi and T. 

 crataegi are very different from those of the other British Lachneid species ; 

 they are mixed with pieces of extraneous matter, and as they are 

 usually spun-up in a crack in the bark, or even under the surface of 

 the ground, they bear considerable resemblance to the cocoons of some 

 Notodonts and Noctuids. 



It is a not uncommon occurrence for two larva? of L. lanestris to 

 spin a common cocoon and for both to pupate therein. Vaughan, 

 Hewett, Foddy, and others, have recorded such, whilst Eussell states 

 that of a large brood, the majority formed single cocoons, others double, 

 while in some instances a general cocoon was formed by three or more 

 of the larva?. Clark records a cocoon of P. trifolii with two exits, 

 containing, however, only one pupa. This is most interesting, because 

 this species does not spin a regular exit to its cocoon, as does Satumia 

 pavonia, in the cocoons of which, the formation of a double exit is not at 

 all unusual. Malacosoma neustri a also makes double cocoons occasionally. 



The pupa is of the ordinary obtect type having the 5th and 6th 

 abdominal segments free in both sexes. It has, however, the dorsal 

 head-piece distinctly developed, and since this is a character specially 

 distinctive of the older forms of pupa?, it suggests strongly that this 

 superfamily is rather low down the evolutionary stem to which it 

 belongs. On dehiscence the head-coverings remain in one piece. 

 Chapman describes the Lachneid pupa as being of stout robust form, 

 rounded at both ends, tapering slightly in the abdominal segments but 

 not to a point or conical extremity, and always terminating in a blunt 

 rounded end, not very reduced in regard to the general size of the 

 pupa. It is usually curved in the abdominal segments, with the 

 convexity forwards, corresponding very often with the form of the 

 cocoon, as exemplified markedly in the pupa of M. rubi, but perhaps 

 never quite absent even in such squat pupa? and cocoons as those of 

 Lachneis lanestris or Lasiocampa querciis. It is, perhaps, an excess 

 of this character that gives the peculiar form of the terminal segments 

 of the Malacosomas. The pupa has no maxillary palpi, but the labial 

 palpi are almost always represented, often notably. The structures 

 observable between the wings ventrally are — antennae, first and second 

 pairs of legs, maxilla? and labial palpi. No femora or trochanters are 

 to be seen, and the third pair of legs is usually quite covered by the 

 wings. There is a clothing of scattered hairs, not hairs of the definite 

 tubercles, but stout bristly points that are distributed over the general 

 surface, and in some species thickly stud certain parts of the pupal 

 skin, being very pronounced, and these often, possibly owing to the 

 movement of the pupa in the cocoon, become covered with larval hairs 

 and the powdery material with which the larva loads the cocoon, 

 forming a sort of felt. The pupa? of Eutricha quercifolia and Gastropacha 

 ilicifolia are good examples of this. In many species, in Avhich 

 the pupa is nearly smooth, it is often much plastered with this cocoon- 

 felt material, and in a species from Sierra Leone, the larval skin is 

 applied to the chrysalis in a similar manner. In a few species there 

 appears to be actually no cutaneous hairs, but in most of these, even 

 in some with a very bright polished surface, some hairs can be found 

 in the infra-spiracular region and on the 9th abdominal segment. The 



