190 THE MOTHS OF THE BRITISH ISLES. 



Haworth, both portions are much reduced in width. Figs. 8 

 and 9 represent two specimens from the Isle of Lewis ; these 

 brownish-grey examples are van obscurata, South. There are 

 intermediate modifications leading up to a form in which the 

 whole of the central third of the fore wings is whitish, with 

 the usual cross lines dingy grey, and some tiny clouds of the 

 same colour around the black discal spot. 



The caterpillar is very like that of the last species referred to, 

 but it is rather smaller in size and rougher in appearance. 

 There is variation in the general colour, from pale fawn 

 through greenish-brown, to dull or bright green, and sometimes 

 the markings are tinged with reddish (Hellins). 



It feeds on bedstraw, in June and July, and a second brood 

 occurs in September. The figure of the brownish, inclining to 

 reddish, chrysalis (Plate 79, Fig. 4), is from a photo by Mr. H. 

 Pvlain, and is twice the natural size. 



The moth is out in May and June, and, in the South especially, 

 again in August and September. It is generally distributed 

 over the British Islands, but so far has not been noted from the 

 Shetlands. 



The range abroad extends to Eastern Siberia and Amurland. 



According to Prout, the earliest name for this species is 

 alternata (Miiller). 



Small Argent and Sable {Xanthorho'e (Epirrhoe) tristafa). 



On Plate 81 are shown three examples of this variable species. 

 Fig. 10 represents the typical form from N. Devon. Fig. ii is 

 a black-marked specimen from Yorkshire, and Fig. 12 depicts a 

 smoky-brown marked specimen from Clydesdale, in which the 

 ground colour has a brownish tinge. All these have the central 

 band more or less entire, but this character may be broader or 

 narrovv'er, and is sometimes divided into two parts, and these 

 reduced to very small proportions ; the white projections into 



