248 BRITISH LEPIDOPTERA. 



their whereabouts. They spin up from the middle to the end of July. 

 Wainvvright finds the nearly fullfed larvae difficult to see owing to 

 their resemblance to leaves, the larvae taking up such a position on 

 the stem as to make this similarity very striking. Bankes notes : 

 "It is remarkable that whereas in some localities the larvae are 

 quite easy to rear, in others even experienced breeders find them im- 

 possible to manage, e.g., they are no trouble at Corfe Castle, yet at 

 Leominster, Hutchinson always fails with them ; the different results 

 may be due to difference of soil on which the birch trees are growing. 

 Those on which my broods were sleeved grew on stiff clay." Tug- 

 well observes of some larvae, bred in 1882 from Rannoch ova, that 

 they went on w r ell until nearly fullfed, when they were attacked by 

 diarrhoea, the frass became moist, &c. Each larva w r as held under a 

 tap of cold water, gently brushed with a camel-hair pencil, rinsed in a 

 stream of dripping water, and put on clean dry food ; every larva 

 thoroughly recovered, and formed a healthy pupa, some imagines emerg- 

 ing in April, 1883, the rest going over. It may be noted that the larvae 

 cling very firmly, and should be searched for, they can only be 

 beaten with difficulty; wild larvae (small) taken June 13th, 1858, at 

 Tilgate ^Tugwell) ; July 7th — 9th, 1858, fullfed, at Tilgate (Merri- 

 field) ; June 3rd, 1867 (Haines); June 14th, July 10th, July 19th 

 (some of these very large), 1891, at Burghfield (Holland). 



Larva. — First stadium (newly-hatched) : Length about 5mm. 

 Head large, rounded, dull black with scattered hairs ; antenna 

 and mouth-parts yellow, rather prominent; a small whitish slip at 

 base of clypeus (? labrum). Body black, skin dull, much wrinkled, 

 scntellum large, but not differing in appearance from general skin 

 surface, except that it bears a large orange patch on either side of 

 median line. True legs orange, but black at base. Hairs taper- 

 ing, simple, bright brown in colour. Skin surface without spicules. 

 Thoracic segments rather larger than abdominals (except 6 and 7, 

 which appear swollen) ; prothorax wider than meso- and metathorax 

 on account of great size of head. Spiracles large with a bold, raised, 

 black, chitinous rim, approaching circular. Tubercles form raised 

 chitinous warts, black, shiny, unlike general skin surface, which is 

 dull. On the abdominal segments, i is large, carrying four setae ; ii 

 small, bearing one seta ; iii large, well above spiracles, with three 

 setae; iv and v raised on lateral flange, in same horizontal plane, 

 just below spiracle, v slightly before, iv slightly behind, the spiracle, 

 but both so close, and the setae belonging to each so scattered 

 that they may be roughly described as a single group on lateral 

 flange ; v bears three, and iv two, setae, the bases of which are large, 

 but the raised skin area bearing them is not so specialised or 

 wart-like as that of i, ii, and iii ; there is a basal group vii, but vi 

 is not traceable ; on the prothoracic segment, i and ii produce setae 

 scattered over dorsal area, but the prespiracular carries 3 setae ; on 

 the meso- and metathoracic segments i and ii are apparently con- 

 solidated into one large tubercle, iii is large, and iv and v are also 

 consolidated ; on the 8th abdominal the two anterior trapezoidals (i) 

 are united and mounted on a tall, fleshy, nearly circular base, ii fall 

 behind these and are not raised. r Fhe meso- and metathorax and the 

 abdominal segments 1 — 8 have three clearlv marked subsegments. 

 First stadium (full-grown) : Now of adult shape, tapering gradually 

 from 1st — 8th abdominal, and more rapidly to head ; the 8th 



