240 BRITISH LEPIDOPTERA. 



than vrhitezzzfersicolora*, Linn. /3. Similar, but with the markings of the hind- 

 wings ill-developed or obsoleteiziab. obsoleta, n. ab. 



3. Forewings deep fuscous-brown ; basal tuft quite white; transverse lines 

 exceptionally dark, contrasting strongly with their white edgings, with the pale median 

 shades, the pale arches of subterminal, and the white apical spots. Hindwings deep 

 orange-brown, median line and external transverse shade strongly marked ; apical 

 spots pure white ; outer margin dark-shaded, with pale nervuresrzab. clara, n. ab. 

 4. a. Forewings dull ochreous-brown, the paler markings suffused with 

 ochreous, apical spots white. Hindwings dull ochreous, dark marginal markings also 

 dull, apical spots entirely lost in ground colour— ab. obscura, n. ab. fi.' Similar, 

 but with the markings on the hindwings ill- developed or obsolete— ab. obscura- 

 obsoleta, n. ab. 



The only described form appears to be the following : 



a. var. lafiponica, Bau, "Stett. Ent. Zeit.," xxxviii., p. 152(1877); Auriv., 

 "Kord. Fjar.," p. 65 (1889); Staud., "Cat.," 3rd ed., p. 125 (1901).— <f. Alis 

 anticis obscure griseo-fumigatis, nigro-notatis ; margine anteriore subtus nigro ; 

 posticis sordide ferrugineo-fulvis, fasciis infuscatis. ? . Alis obsolete cinereo 

 fulvoque nebulosis. $ . The forewings dark smoky-brown with a good deal of 

 black ; the white markings of the type-form usually only just indicated, sometimes 

 entirely wanting ; margins of underside black. Hindwings dirty red-brown with 

 darker bands. % . Pale drab-brown with a good deal of black, the white portions 

 with a weak tinge of brown ; generally the normal black area is more extended, 

 especially on the undersides of the wings. The femora, dark-brown in the type, are, 

 in the variety, shiny black. The white of the thorax is mixed with brown. The 

 larvae were obtained by Kricheldorff in Swedish Lapland last year, on a birch bush (Bau). 



Egglaying. — The eggs are laid side by side along a twig of birch, 

 their long axes transverse to that of the twig, and a second and even 

 third row may be placed on top of them. In laying her eggs, the moth 

 feels the twig and the preceding egg with her ovipositor carefully getting 

 it into position, in a way difficult to describe, passing it in some 

 degree round the twig, the extremity of the ovipositor corresponding 

 with the micropylar end of the egg, which is gradually thrust out 

 a short way and then rapidly into its position, in a way that makes 

 one sure it cannot possibly reach and stop at its right place, which 

 it nevertheless does, the cement that afterwards holds it so firmly in 

 place, apparently acting as a perfect lubricant (Chapman). The 

 eggs found in the woods are laid in little batches of 6 to 8 or so, 

 in double rows, on small outside twigs of birch, 2 ft. — 4 ft. from the 

 ground ; the eggs are pale at first, but darken in a day or two to 

 a purple-brown colour, just like the birch twigs (Holland). The ova 

 are laid in rows, side by side (somewhat like those of Trichiura 

 crataegi), the number in a row varying considerably (Bacot). In 

 nature, a batch of eggs usually numbers 10 — 18 (very rarely 20 or 

 more go to form a batch), attached in a double row to birch twigs on 

 the outside of the bushes ; when a 2 has deposited one small section 

 of her eggs, she flies from 15 yds. — 20 yds. before selecting another 

 bush ; after darkening, the eggs are most perfectly protected (Clarke). 

 A 3 and $ emerged in the afternoon of February 27th, 1893, an< ^ 

 paired almost immediately; they remained in cofvld till 10 p.m. the 

 same evening, and at 10.45 p.m. the $ began egglaying on dead 

 twigs of birch, to which they were fastened by their long sides in 

 rows of from 6 to 10; in one case a second row was laid on the first. 

 After several rows had been thus laid, cracks in the box in which the 



* Linne's original description evidently refers only to the <? . We have 

 selected this as the typical form of the male, being, at any rate with us, the 

 commonest 



