18512. J 119 



costa, serve amply to distinguish it. It was quite new to Mr. Staiutou. 

 Mr. Fletcher, too, whose insight into these puzzling insects is con- 

 siderable, seems also to be unacquainted with it. To a certain extent 

 local, it will probably be found wherever the Luzula sylvatica occurs 

 in any quantity. In my own immediate neighbourhood the plant 

 grows only at Haugh Wood, one of the largest of Herefordshire 

 woods, and a remnant, to all appearance, of the primitive forest land. 

 Happy is the Naturalist that has such a place within his reach, with 

 its dense covert, its rare and interesting vegetation, its boggy runlets 

 and varied surface ! Here it is that sijlvaticella may be taken flying 

 in the day time among the patches of the wood rush at the end of 

 May and beginning of June, and here, of an afternoon, the females 

 may be seen laying their eggs deep in the rush flowers, after the 

 manner of these species. 



The larva is of the usual Coleophorous type. In this type the larva is short, 

 rather stout, with weak ill-developed ventral legs, a small head, powerful 2nd seg- 

 ment, and large and strong plates ; the latter not being confined to the 2nd and 

 anal segments, but being present on the 3rd, and often on the 4th as well. The 

 large plate on 2nd has the usual dividing line down the centre, but the plates on 

 3rd and 4th are not only divided longitudinally, but each lateral half is again 

 divided obliquely in such a way that, of the four resulting parts or sub-plates two 

 are inner and posterior, and the other two outer and anterior. This division, I may 

 add, follows the line of a natural sulcus that crosses the back of the segment in this 

 situation. Frequently the full complement of sub-plates is not present, one or other 

 pair being suppressed, and in the case of the 4th segment the suppression may even 

 extend to both pairs. In addition to the dorsal plates, each thoracic segment is 

 furnished with a plate in the spiracular region. 



This consolidation of the thoracic segments is found in case-bearing 

 larvae generally, as well as in some that burrow in the ground like the 

 HepialidcB, and has commonly been attributed to the friction to which, 

 under the peculiar circumstances, this part of the body is exposed. 

 Natural as the explanation sounds, I am not sure that it is the true 

 one. It is well to remember that strength of integument is usually 

 correlated in insects with muscular development. There can be no 

 question either that the thoracic segments have here especially heavy 

 work to perform, since, in the case bearers, the transportation of the 

 whole animal, case and all, devolves upon them, and, in the burrowers, 

 the same segments are the chief agents in tunnelling through the soil. 

 I would, therefore, suggest that these chitinous deposits, instead of 

 being the outcome of friction, are the result of the increased develop- 

 ment of the muscles and their exaggerated pull and strain upon the 

 integument, just as in our own skeletons, the bigger the muscles the 

 bigger are the bony ridges with which they arc connected. 



