336 LÉPIDOPTÉROLOGIE COMPARÉE 



Costa. In most spécimens, the médian line is much nearer the 

 second line than to the first. There is generally a white discal 

 spot surrounded by blackish scales. The subterminal white band 

 lias a strong black suffusion before it, and a weaker one after. 

 In a fair percentage of the spécimens, the terminal suffusion is 

 absent and then the insect assumes a very différent appearance. 

 I call this form ab. extincta. The same type of markings holds 

 on the hindwings, except that the first line is absent and the 

 médian one nearly so. The discal spot is clearly marked. On 

 ail the wings, the veins tend to be outlined in dark fuscous. The 

 termina of ail are quite rounded giving us a crescent as the shape 

 of those of the forewings and an almost semicircular curve for 

 the hindwings. 



The thorax is covered densely with almost white fur above, 

 tending to become brownish below. The patagia too, may be 

 out-lined in brown. The abdomen is brown, more or less densely 

 covered with greyish hairs or fur. 



The genitalia (PI. B, Fig. i6) are very simple but are quite 

 satisfactory, for they afford us excellent characters for separating 

 the species. 



The valves are very short for the size of the insect i. e. when 

 compared with other members of the group. Tlie upper margin 

 or Costa of the valve, is concave whilst the lower is slightly so 

 for five sixths of its length, when we hâve a strong upward curve 

 to the rounded tip giving the valve roughly the shape of a 

 pruning knife. The costal ridge of the valve is wide and is 

 slightly raised. 



The uncus is much the same as in the other species except that 

 the point is longer. The gnathos (the broad chin like plate below 

 the uncus) is wide with a broad, rounded and slightly roughened 

 tip. It is notched at the base and its surface is squamous. 



The oedeagus is short and stout whilst the vesica is provided 

 with a few clawlike cornuti. 



The tergite of the 8th abdominal segment is slightly thickened 

 and is divided into two lobes. 



