STEREHOPTERIX HIRSUTELLA. 425 



Case. — $ . From 15mm. -20mm. long (probably somewhat damaged 

 and hence less than true length), somewhat broader at the anterior 

 and narrower at the posterior end, and as the anterior end is much 

 more thickly clothed with irregularly laid on pieces of lichen, wood, 

 and other vegetable debris, it looks somewhat conical in shape. The 

 case is made of loose white silk, the pieces of material attached are 

 often fastened crosswise, and the posterior end has an almost un- 

 clothed tubular portion that is rather conspicuous. Heylaerts describes 

 the case as 22mm. -28mm. long, 4mm. -8mm. wide, lined internally 

 with silk, the anterior end covered with small pieces of leaf, in the 

 centre with larger pieces of grass-culm or seed husks ; the posterior 

 end unclothed ; the hinder end forms two valves, which are opened by 

 the larva to get rid of its cast skin, excrement, &c. The male case is 

 longer and thinner, the female case shorter but broader. Wood also 

 notes the male case as being much more slender than that of the 

 female, whilst Hofmann says the former has a rougher appearance, 

 and has a white silken tube at the anal end, on the outside of which, 

 as in Ptilocephala atra (angustella), the cast skin is hung. The female 

 cases are smoother, and the posterior white silken tube is absent. 

 Bruand observes that the cases vary considerably, being sometimes 

 covered with little straws placed perpendicularly to the axis and form- 

 ing a structure something like a pincushion, like that of tabanella, but 

 less regular ; at other times it is clothed with twigs, little splinters 

 of wood, pieces of cork, &c. In almost all cases, one sees at the lower 

 extremity three small whitish streaks placed triangularly and extend- 

 ing up the case for almost a quarter of its length ; these white stripes 

 are only the silk of the sac or real case, which is naked at these places. 

 The different cases might easily mislead one into supposing that they 

 belonged to different species, but there appears to be no difference in 

 the imagines. The straw cases are generally found on sloe and nut- 

 bushes ; those made of splinters are found on willow, aspen and oak. 

 Barrett notes the case as rather broad in the middle, narrowing rapidly 

 at both ends, covered with dry morsels of leaf, capsules of sallow or 

 plantain, morsels of dried stalks or any other vegetable material, which 

 is placed crosswise or in any direction rather than lengthwise. Stand- 

 fuss says that the case is clothed with the most diverse materials, with 

 the fallen brown scales of leaf buds, small pieces of bark, of fine stems, 

 small flowers, all placed so irregularly that one cannot say whether 

 they are attached lengthwise or vertically. The male case has a rather 

 long unclothed white silken tube, on which, two or three weeks before 

 emergence, the larval skin may be found hanging ; the ? case lacks 

 this tube. 



Habits of larva. — Heylaerts notes that eggs laid by females in 

 his possession hatched July 17th, 1870, that the young larva? were at 

 first gregarious, but separated later, moulted first on July 29th, then 

 grew rather rapidly, moulted again on August 21st, again on September 

 17th, and then on October 7th ; they commenced to hybernate on 

 October lGth, began to feed again the following April, and pupated 

 during May, emerging in June and July, all males. Standfuss states 

 that in Silesia the species matures in one year, but Mitford, whose eggs 

 came from North London in August, did not breed imagines until the 

 next June twelvemonths, and Wood observes that in Haugh Wood, the 

 small yearling cases are sometimes common on the leaves of oak, 



