14 Proceedings of the 



is used by the insect whilst within ; it is applied, owing to the 

 peculiar masking of the head and face, over a larger circle than could 

 possibly be the case otherwise within the same time, softening the gluten 

 of the silken threads and the intermingled wooden or earthen particle! 

 interwoven for the purpose of strengthening the outer wall, which then 

 yields readily enough to the struggling prisoner, who, in escaping, by the 

 aid of the mask equally protects the as yet tender head from harm and 

 stickiness of the still damp threads of the cocoon. Is not some such action 

 get up in Lanestris 1 That interesting enigma has still to be worked out. 

 The diminutive cocoon for the size of the moth, and the minute pin-hole 

 opening, assumed to be for air, have attracted passing notice; but tho 

 emergence is not recorded. It is an anomaly; but has it a dipterous 

 habit ? That is what we want to know ; and those residing in the London 

 district, where the insect is pretty common, might well work out its 

 history — not known because not looked into. Although less silk is used in 

 their construction, some of the cocoons of the NoctusB are scarcely less 

 solid in their entirety than those of the Cuspidates. The group, from its 

 sameness of habit, has small charms for me ; and, as I am speaking of 

 things that have come under my own observation, I cannot tell if they 

 emerge in the same way. I am inclined to think, however, that pressure 

 alone causes a place of exit to be made from within ; for an examination of 

 the hard cocoon of the Sharks or Dianthecije will show the smaller end to 

 be excessively thin. It is true that I have seen none that have been opened 

 soon after building ; but were the wearing down to be attributed to friction 

 on the part of the pupa, the latter must equally suflEer with the envelope it 

 destroys, which does not seem to be the case. The surrounding web or 

 cocoon of the Geometer is, as a rule, very slight, and offers little impediment 

 to the escaping insect ; nevertheless, the pupa-case itself is as completely 

 broken up as in any o£ the foregoing. Some of the species emerge below 

 the surface of the ground, pushing through at the same time ; of such 

 Vitalbata and Comitata may be taken as examples; but the images of these 

 and many more insects of this habit may generally be recognised by the 

 finer scaling on the wing-disc. When reared in confinement the pupas 

 should be dug up and placed on the surface if good specimens are desired. 

 Like Vinula, and evidently for the same purpose, the pupa-case of Comitata 

 breaks, so as to form a shield or protection to the head, thorax, and wings, 

 whilst forcing its way through the soil. As might be expected in so large a 

 family, great diversities in extrusion may be seen, in some species so little 

 damage being done to the chrysalis that one has to look closely to discern 

 which is the empty shell ; in others they are much broken, and among«t 

 the genus Eupithecia (Pugs) the front is split oi3E in the same manner as 

 amongst the Sphingids . There is but little to remark in the succeeding 

 groups. The genus Coleophora, one of the Tineina, make no preparation 

 for the final change, beyond fastening the mouth end of their case firmly to 

 a stem or leaf, after which they turn round, and, having assumed the 

 chrysalis stage, in due time escape through the tip of the case, which, again 



