328 THE MOTHS OF THE BRITISH ISLES. 



the outer one. In some specimens there is a distinct sub- 

 marginal line, but this character is only faintly in evidence as a 

 rule, and occasionally it is entirely absent. (Plate 143, Fig. 6.) 



The caterpillar feeds in June, sometimes earlier, on bracken 

 or brake-fern {Pteris agiulina). It is olive green marked with 

 reddish brown lines, and there is a whitish line under the black 

 spiracles. 



In most English and Welsh localities where bracken is 

 plentiful, this moth should be found in May and June ; also in 

 the south of Scotland, but its occurrence in that country north 

 of Clydesdale appears to be only casual. It is common in 

 several parts of Ireland. 



The distribution abroad includes Amurland and Japan. 



Latticed Heath {Chiasmia {Strenid) dathrata). 



In its ground colour this species (Plate 143, Figs. T^^ 6 j 9 ?) 

 varies from ochreous of some shade to white. The dark-brown 

 or blackish cross lines and veins give a latticed appearance to the 

 wings, hence both the Latin and popular names for this insect. 

 There is much variation in the width of the cross markings ; 

 sometimes two or more unite and so form bands ; more rarely, 

 perhaps, the outer lines are absent, and the others broken up 

 into dashes ; or the blackish cross lines may be slender and the 

 veins remain of the ochreous ground colour (ab. radiata, 

 Haworth). A less frequent aberration has the wings dark 

 brown or blackish all over, except a row of whitish or ochreous 

 spots on the outer margins (ab. nocturnata^ Fuchs = nigricans, 

 Oberthiir). 



The caterpillar, which feeds on clovers and trefoils, is green, 

 with white lines along the back and sides ; the slightly notched 

 head is rather glossy, and the mouth is brownish : June to 

 September, in two broods. 



The first generation of the moth is out in April and May, and 



