LÉPIDOPTÉROLOGIE COMPARÉE 335 



Our British spécimens (var. Britannica, mihi) hâve much greyer 

 markings tending to be ob&olete inward from the praesubterminal 

 suffusion. 



In var. Rossica (mihi) from the Ural Mountains, the spécimens 

 are very small with strong dark markings and a Ime-like subter- 

 minal band. For the British form almost totally suffused with 

 smoky black, I propose the name obscur a. 



Ithysia alpina (Sulzer). PI. CLXII, Fig. 1583. 



VVing expanse : 37-39 mm. 



This species was first described and figuied by Sulzer in 1776, 

 from spécimens taken in Switzerland but, when the plat-^s were 

 reissued in by Roemer in 1789, he emended Sulzer's name to 

 alpinaria and this name was used for the same form by Herrich- 

 Schâffer, in 1850 and by Millière, in 1864. In 1840, however, 

 Boisduval described the species as Bombycaria, and in this he 

 was followed by De la Harpe, in 1852. Guenée too, used the same 

 name. 



Alphia is most readily differentiated structural ly from the 

 others by its very weakly pectinated antennae (PI. D). T lie pec- 

 tinations are exceedingly short, and, on at least six joints, thcy 

 are absent whilst those on the 7th are barely discernible. 



The ground colour of the wings is white (with a slight gloss) 

 very faintly speckled with brown in some spécimens. The fore- 

 wings are traversed as usual, by the three lines and the subter- 

 minal band. AU of the lines are thickened, more especially on 

 the veins and before vein I. This thickening is especially marked 

 on the médian line and extends for a space of 3 mm. along the 

 Costa on this line. The directions of the first and médian lines 

 call for little comment but that of the second line is exceedingly 

 important. It proceeds from the inner raargin, through the lower 

 angle of the cell to vein 5, quite regularly and then passes with 

 a sweeping curve almost the exact quadrant of a circle to the 



