10 LEPIDOPTERA. 



head and neck-ridge greyish-white, dusted with pale brown •;. 

 thorax rather robust, of the same colour and dusting but 

 whiter behind ; abdomen similar, with a white edge to each 

 segment; lateral and anal tufts broad and rather con- 

 spicuous. Fore wings very broad but pointed ; costa arched 

 at the base, thence very nearly straight ; apex sharply angu- 

 lated ; hind margin oblique, gently curved, and a little 

 expanded ; dorsal margin very slightly rounded ; greyish- 

 white minutely stippled in oblique lines with grey atoms ; 

 basal line grey, slender, a little curved but indistinct : first 

 line oblique, straight to near the costa, where it is bent back ;. 

 second line somewhat parallel, but more sinuous and indented, 

 and twice or tlirice tcothed outwardly ; the space between 

 these two lines, which are grey, forms a central band of 

 darker grey than the ground colour, yet not very dark, and 

 rather divided by internal lines parallel to the first and 

 second, also enclosing two black dots as a discal spot ; hind 

 marginal region clouded with gre}% which is divided into 

 stripes by the whiter rippled subterminal lines ; of this the 

 hollows are, in some specimens, filled with darker grey ; 

 from this [an oblique shade, often dotted with brown or 

 reddish-brown, runs into the apex of the wing ; cilia grey 

 shaded with white. Hind wings long, moderately broad, 

 rounded behind ; smoky-white or pale smoky-grey, whiter 

 toward the base, and^very faintly banded with alternate 

 whiter bands and greyer curved lines ; cilia greyish-white. 

 Female very similar, but with the body a little shorter and 

 thicker and much more pointed. 



Underside of the fore wings shining smoke-colour; costa 

 tinged w-ith light brown. Hind wings of the same smoky 

 tinge. Body greyish-white ; legs grey ; tarsi darker grey. 



Usually very constant in colour and markings, except 

 that local variation takes place according to the geological 

 formation of the locality, specimens from the chalk districts 

 being usually much whiter than those from the greyer 

 mountain limestone of western districts. There is occasional 



