BOARMID/E—CABERA. 357 



rounded ; silky and glistening, snowy-white, faintly dusted, 

 along the costa and hind margin, with minute black-brown 

 scales ; the first line rather curved, the second oblique and 

 very straight, the central line between them almost equally 

 so, all three of a faint undertone of grey-brown or smoky- 

 grey ; no other markings ; cilia white. Hind wings broad 

 and rounded, of the same silky-white, faintly dusted with 

 blackish scales ; and crossed by two similar transverse lines, 

 both very slightly curved. Female with simple antennas and 

 stouter body, not otherwise differing. 



Underside of all the wings silky-white, the costal region of 

 the fore wings dusted with black-brown. Body and legs 

 greyish-white. 



There is variation in the number of transverse lines on the 

 fore and hind wings, an additional one appearing as the 

 ordinary basal line, sometimes therefore there are four 

 equidistant lines on the fore wings and three on the hind. 

 In other examples one or move of the ordinary lines disappears, 

 until in rare instances the insect is of a pure white devoid of 

 markings. Such a specimen, of a glittering brilliancy of white- 

 ness, was reared by Mr. R. Newstead, from Delamere Forest, 

 Cheshire, in 1887. Another condition in which it is without 

 the lines is where the dusting of dark atoms has so enormously 

 increased that the wings ?nv wholly, or almost wholly, leaden 

 black. This is rare, but specimens exist in various collections, 

 and occasionally the costa of the fore wings alone is white. 

 Intermediate specimens are very rare, but in the North of 

 Ireland a tendency in this direction is shown, a peculiar grey 

 shading suffusing the wings, while the lines are tinged with 

 brown. 



Besides these forms there is a peculiar, almost structural 

 variety, which was long looked upon as a distinct species under 

 the name of C. rotundaria. In this the fore wings are more 

 rounded, sometimes very much so, and their first and central 

 lines drawn near together, or actually fused, giving it a 

 notably different appearance. But strong suspicions as to its 



