61 



illustration of my remarks, I propose to confine myself to British 

 species, and therefore what are generally recognised as silk-producing 

 species are inadmissible. Yet even though we may have none that 

 spin their cocoons in the orderly fashion employed by Bombyx nwri, 

 that allows of the silken threads being unwound ; nevertheless, in 

 many of them the silken threads are there, but stuck together, 

 tangled, or it may be so mixed with other substances as to be 

 difficult to determine. 



Take the cocoon made by Satnniia parouia for example, a 

 remarkable construction consisting of an inner pear-shaped envelope 

 which at first sight appears to be a tongh parchment-like skin, but 

 which, upon examination under the microscope, is found to be made 

 up of numberless silken threads so interwoven and matted together 

 as to form a compact mass giving the skin-like appearance. This 

 is surrounded by a quantity of loose, coarse, silken threads, by 

 which it is attached to twigs or other substances, a conspicuous 

 object enough when detected, yet so hidden among the heather, 

 brambles, or what not, amongst which it is made as to be easily 

 overlooked, or if seen, to be passed over as a bit of detached sheep's 

 wool. The conspicuous, shining cocoon of Anthroceia nlipenduUc 

 is also constructed of silk, but in this case it is of a very fine texture 

 and so closely woven that it is exceedingly tough, such protection 

 as it may afford to the enclosed pupfe apparently being due to th-s 

 fact, its usual position, well up a grass-stem, showing no attempt at 

 concealment. (See Plate IV.) 



It would be impossible in the course of a short paper to enumerate 

 all the species that build interesting structures for their pup^e. I 

 therefore propose to mention chiefly those that have come under my 

 own notice. The Rhopalocera may be passed over, as practically none 

 of them can be said to construct a "habitation," nor need the larger 

 Sphingidae detain us, but among the Sesiidfe there are some interesting 

 examples. They are as a rule internal feeders, the larvte of some of 

 them burrowing in the branches or solid wood of trees, the burrow 

 formed by the feeding larva being used as the pupal home, but the 

 hole at the end of the burrow from which the imago is to emerge is 

 often covered by a "cap " cut out of the bark, this is well seen in 

 the case of Sei>ia and rent form is, also of Truc/iilinut crabroniforniis. 

 Some others that feed chiefly under the bark make tough pupal 

 cocoons in the ends of the burrows by working some of their gnaw- 

 ings of bark in with the larval silk ; of these (SV.sm scoliifurmis and 

 S. culiciforinis are good examples. Those that are root feeders, such 

 as S. ichneumoniforiiris and S. chnjsidifortnis, construct similar but 

 less solid cocoons, generally in the mine or just above it in the 

 crown of the root, not infrequently projecting above it, yet completely 

 hidden by the branching stems or leaves of the plant. 



Among the bombyces we find some very remarkable structures, 

 and that of Hylophila bicolorana is one of the most interesting. The 

 larva is full-fed in June, and constructs its cocoon on the back of a 



