1884.] 237 



From long and careful observation, and the examination of vast 

 numbers of specimens, it seems certain that the attempt to define the 

 species of Sciaphila by means of their markings is practically hopeless. 

 In most of the species the ground-colour is grey or white, or even grey 

 in the male and white in the female; and the markings — of some shade 

 of grey — consist of a curved, elbowed, or abbreviated fascia near the 

 base of the fore-wing, representing the exterior margin of the usual 

 basal blotch, an oblique central fascia angulated and indented, and 

 apical blotches indicating a third fascia across the tip, and all these 

 are so irregular, so uncertain, so broken up by interruptions, and 

 obscured at times by dark scales or round dots, that any hope of 

 defining the species by their means must, I think, be abandoned. Tet 

 they may be used as secondary characters in confirming distinctions 

 arrived at in another way. 



"Wilkinson, in his work, appears to have overlooked the reliable 

 characters a:fforded by the fonns of the fore-wings, which really seem 

 to be tolerably constant in the different species. He certainly notices 

 the peculiarity in Splialeropfera ictericana of the nearly straight costa, 

 and uses it in separating this species as a distinct genus ; but he seems 

 not to have noticed that the costa of ictericana, (J , is no straighter than 

 that of several species of Sciaphila, and the only really distinctive 

 character in Sphaleroptera is the unsatisfactory one that the $ also 

 has the costa straight. 



The genus appears to bear sub-division into groups, thus : — 



1. Fore-wings short and broad : nubilana, ahrasana. 



2. Fore-wings elongated, broad, costa gently arched : virgaureana, 



aUernella, octomacuJana. 



3. Fore-wings broad, costa strongly arched before the middle : sinuana. 



4. Fore-wings elongated, rather ovate : pascuana. 



5. Fore-wings elongated and narrow, costa slightly arched : conspers- 



ana, suhjectana, communana, Wahliomiana ?, ictericana. 



6. Fore-wings very long and narrow, hind margin very oblique : 



Penziajia, Colquliounana ?. 



With the assistance of these characters, it may be possible to get 

 some idea of the different species, or, perhaps, in some cases, perma- 

 nent varieties. 



nubilana, Hiib. — Fore-wings each 3 lines long, by 1| broad, of 

 fairly equal breadth, with short costa, blunt apex, and rounded hind 

 margin. In the female rather broader and still rounder. A dark 

 grey insect, accurately described by Wilkinson. 



