Satin Wave

The ground colour is white with strong silky gloss, the lines grey, seldom strongly expressed, on the other hand usually all present, thus numbering five on the forewing and four on the hindwing; the outermost line (distal shading of subterminal) the oftenest absent; all except the median are parallel with the distal margin, but slightly wavy; the median on the forewing is usually somewhat oblique, but occasionally almost parallel with the others; that of the hindwing runs straighter across the wing, instead of following the curve of the strongly convex distal margin. Cellspots and terminal line wanting or rarely the former present, minute; fringe usually with a series of minute black dots at the base, which are sometimes in part, more rarely entirely obsolete. Forewing beneath often with a smoky suffusion, either basally or all over; median and postmedian lines present, often well developed; a small discal dot present. Hindwing beneath white, with discal dot and postmedian line. Male antennal ciliation little longer than diameter of shaft; hindtarsus short. Not on the whole an extremely variable species, except in size; there is, however, a great deal of trivial variation, i.e. …