124 LEPIDOPTERA. 



men smoky-brown, abundantly covered from the base to the 

 middle with long smoky-white hair-scales, behind with shorter 

 smoky-brown ones ; on the back of the basal segment is a 

 large and conspicuous dark-brown crest tipped with white, 

 and on the third segment another, a very short one occupying 

 a similar position on the second segment ; lateral and anal 

 tufts small. Fore wings long and pointed at the tip ; costa 

 very gently arched at the base and apex, nearly straight 

 between ; the apex sharply angulated ; hind margin oblique, 

 slightly crenulated, straight to near the anal angle, then 

 rounded off ; dorsal margin gracefully curved ; colour shining 

 silvery-grey, marbled with dark purplish-grey and black ; 

 basal line restricted to two black curves edged outwardly 

 with white ; first line very obscure, oblique, rather direct to 

 the median nervure, above this much angulated, yellowish- 

 white, clouded on each side with black ; second line obscure, 

 dusky-white edged with light brown, twice deeply indented 

 near the dorsal margin, above this direct and oblique ; sub- 

 terminal line abundantly angulated, black, edged outside with 

 purplish-white, and bounding or dividing a large shining 

 slate-black cloudy stripe shot in patches with silvery reflec- 

 tions, which runs into the apex, but is sharply cut off below 

 by the ground colour ; orbicular stigma oblique and narrow, 

 but very indistinct ; attached to it from below the median 

 nervure is a conspicuous burnished silver Y (whence the 

 moth receives its names), which is sometimes contracted, but 

 rarely, if ever, broken ; it is set off by a deep black edging 

 which shades off outwardly, but all the adjacent portion of 

 the wing is clouded with black, purple-grey, or purple-brown ; 

 reniform stigma placed far back, deeply constricted, mainly 

 indicated by a faint silvery margin ; cilia pale grey barred 

 and spotted with black-brown. Hind wings broad, with 

 sinuous and faintly crenulated hind margin, smoky-white to 

 the middle, often with a yellowish gloss, nervures smoky- 

 brown ; hinder half of the wing occupied by a very broad 

 ill-defined black or smoky-black band ; cilia white, spotted 

 with black-brown. Female very similar. 



