316 THE ENTOMOLOGIST. 



blackish or brownish sufTusion. The hind wings are much the 

 same, except that the first hne is only exceptionally present. 

 Both wings have a white discal spot, surrounded by a blackish 

 ring on the transverse vein. These spots may be absent. 



I have previously suggested that alpina and grcecaria should 

 be separated from zonaria, but I am sure now that the separa- 

 tion, as far as alpina is concerned, was premature. This species 

 I consider to be generically the same as zonaria. There are a 

 few structural points, such as the stronger antennal pectinations 

 and the absence of cornuti on the vesica in the genitalia, which 

 might be used to separate the two species italica and grcecaria 

 from Ithysia under the generic name Melanocoma, but I prefer 

 to call all four Ithysia. 



The relation between the forms or species has been very 

 obscure in the past, partly owing to the difficulty of obtaining 

 them, and partly on account of their great variability. I hope 

 that this paper will clear up this confusion. I shall deal with 

 the males of each species separately, but for the purpose of 

 comparison I shall treat of the females as a whole. 



Ithysia zonaria (Schiff.). — This species has caused no con- 

 fusion, as it is very widely distributed, being found throughout 

 North and Central Europe, and extending even to Armenia. The 

 type of the species, as found in Central Europe, has very dark 

 markings^ — so dark, indeed, are they that they are nearly black. 

 Our specimens (var. hritannica, mihi) have much greyer mark- 

 ings, which tend to be obsolete inward from the prsesubterminal 

 suffusion. 



In var. rossica (mihi), from the Ural Mountains, the specimens 

 are very small, with strong dark markings and a line-like sub- 

 terminal band. 



For the British form, almost totally suffused with smoky 

 black, I propose the name obscura. 



I. ALPINA (Sulzer). — I. alpina was first described by Sulzer in 

 1776 from specimens taken in Switzerland, but when the plates 

 were reissued by Eoemer in 1789, he " emended " Sulzer's name 

 to " alpinaria," and this name was used by Herrich-Schiiffer in 

 1850, and MiUiere, in 1864, for the same species. In 1840, 

 however, Boisduval described the species as bombycaria, and in 

 this he was followed by De la Harpe in 1852. Guenee, too, 

 used the same name. 



Alpina is most readily differentiated from the others struc- 

 turally by its very weakly pectinated antennae. The pectina- 

 tions themselves are exceedingly short, and at least six joints 

 are without them, and those on the seventh are barely dis- 

 cernible. The ground colour of the wings is a slightly glossy 

 white, very faintly speckled with brown in some specimens. The 

 fore wings are traversed as usual by the three lines and the 

 subterminal white band. All of the lines are thickened, more 



