312 BRITISH LEPIDOPTERA. 



of the ovipositor allows the female to deposit her eggs at the bottom 

 of the case (which it leaves on emergence), afterwards covering them 

 with down from the anal extremity." 



Ovum. — About '80mm. in length, and -37mm. in width ; roughly 

 oval, but variable in shape, some being long and cylindrical, others 

 quite ovoid. The egg is of a pale straw-colour, slightly wrinkled from 

 dessication, but with no structural sculpture. Each egg is seen, under 

 a microscope, to be covered as it were with wool, i.e., there is a network 

 of wool fibres over each egg, to about the extent of twenty meshes to 

 the length of the egg, yet there is in reality so little that without 

 a microscope it is invisible (Chapman). 



Case. — Cases extend from 9mm. -12mm. in length, cylindrical in 

 shape, surrounded somewhat regularly with straws, which are almost 

 of the same length as the central silken cylinder, four longer straws 

 extend 3mm. beyond the others at the posterior end and give it some 

 appearance of squareness. The case is similar to that of F. casta, but 

 larger, and made of coarser materials. The $ cases are frequently 

 without the projecting straws (or they project to a less extent) and are 

 usually broader, and hence appear stumpier than the $ cases. Bruand 

 notes the case as "composed of pieces of straw or of dried grass culms, 

 placed longitudinally and almost parallel. It is stout compared with 

 its length and more bulky than those of F. inter mediella, B. comitella, 

 and M. saxicolella. This fact inclines one to the opinion that this is 

 the species that Eeaumur wished to indicate by his fig. 8. The case 

 represented by his fig. 9 (of the same plate) resembles that I have 

 found on rocks (more particularly on the road to Paris, at the Croix 

 d'Arenes, near la Butte), i.e., it is shorter although the straws are 

 equally coarse." The imagines from these cases he found indistinguish- 

 able. We suspect that this difference was largely a matter of sex. 



Habits of larva. — Some larvae in our possession hatched July 

 11th, 1899, and immediately made themselves minute cylindrical cases 

 of the silk in which the eggs had been enveloped, and which they 

 carried about in a vertical position at an amazing pace for such tiny 

 creatures so handicapped. They feed up slowly all the summer and 

 autumn, hybernate during the worst of the winter like their congeners, 

 and are rarely seen again in spring until they are found on the rushes, 

 grass culms, tree-trunks, or rocks, spinning up preparatory for pupation. 

 Bruand says that the bybernated larvae reappear with the first fine 

 days of spring, and may be met with at the foot of rocks facing east or 

 south and upon old walls covered with grass and bramble. In the 

 Doubs dept. it is generally fullfed in April (at the commencement of 

 the month only in early seasons). 



Larva. — The larva is dirty yellow, or very pale brown ; approach- 

 ing slightly to vinous, with two dorsal lines of an intense vinous-brown, 

 between which may be noticed, on each of the first three segments 

 (thoracic), two dark brown dots. Above the stigmata is an elongated 

 spot of the same tint as the dorsal lines. These spots and lines are 

 much more strongly marked on the pro-, than on the meso- and meta- 

 thorax, whilst on the fourth they are obliterated. Its head is horny and 

 shining, of a pale brown or vinous tint with five lines and two blackish- 

 brown dots on each cheek, also another spot of the same colour 

 above the mandibles ; the upper line is bent in an opposite direction 

 to the lower ; they both originate against the 1st segment and run so as 



