Phylogeny and Evolution of the Lepidoptera. 571 



and was developed from the earlier and simpler method, 

 is a matter deserving of investigation, and will no doubt 

 yield many interesting facts. That I say nothing about 

 it is due to sheer ignorance, and not the ostensible reason 

 that it is outside the LepldojHera. 



In the Micropterijges the jaws of the pupa not only 

 rupture the cocoon, but appear to bo the most active 

 agents in dragging the pupa through the opening in the 

 cocoon and through any superincumbent earth, being 

 merely assisted by the vermicular action of the abdominal 

 segments, and we find in accordance with this circum- 

 stance that the pupal envelope is still very thin and 

 delicate, and has little or no hardening or roughness by 

 which to obtain a leverage against the walls of the 

 channel of escape. 



There are no doubt many lost families at this point, 

 and we do not find precisely the next stage in the pro- 

 gress of pupal evolution. In all other instances we not 

 only find the pupal jaws absolutely lost, and also a general 

 hardening of the pupal skin, with a development of 

 roughness across the abdominal dorsum, but, perhaps, 

 inevitable with the hardening pupal skin, we find also a 

 considerable consolidation of previously separate and 

 movable parts. 



No doubt it was soon found that great assistance to 

 the emergence from the cocoon was obtained by a 

 hardened and rough abdominal integument, and this 

 directly led to the further step that by a little weakening 

 or valvular structure of the cocoon, the jaws might be 

 absolutely dispensed with. 



In Limacodes we find all the segments of the abdomen 

 still free, and the appendages, though fused together, 

 are fused so shghtly as to be easily separated without 

 injury, and the cocoon is provided with an easily separated 

 lid. 



In the lower Adelids the segments are more fused 

 together, and by aid of a beak more or less developed, 

 and the cocoon being made of a valved larval case, exit 

 from the cocoon is achieved. It would seem that a beak 

 was early adopted as a weapon for breaking open the 

 cocoon, as it exists in nearly all the lacompletx, except 

 the Limacodid and Nepticulid section. 



In all these instances the pupa emerges from the 

 cocoon precisely as in the MlcropteryQes, that is, the moth 



