222 THE ENTOMOLOGIST. 



Cidaria russata. — This variable insect is remarkably uniform 

 in coloration in the Hebrides ; many scores have been brought 

 by the collector, but the variation amongst them is slight. Grey 

 and black are the prevailing colours, and the usual red markings 

 are but very faintly shown. All the specimens too are dwarfed. 

 There is often seen amongst English examples of C. russata 

 many more varieties from the eggs of one female, than the whole 

 of the specimens from Lewis exhibited. I regard this as one of 

 the most remarkable instances of a variable insect becoming 

 uniformly of the colour of the rocks on which it rests. 



Mr. Meek's laudable enterprizes of sending collectors to 

 Ireland, Scotland, the Isle of Man, the Outer Hebrides, and the 

 Shetlands have given an impulse to the study of local variations 

 amongst the Lepidojitera of those localities. Far more interest 

 attaches to such varieties than to mere aberrations, which may 

 never be repeated, and are simply monstrous. Collections should 

 be arranged to keep the specimens obtained from different 

 districts distinct, so that where insects are affected by the 

 geological condition of their surroundings it should be clearly 

 shown. 



There is another even still more interesting line of research 

 in the collecting of insects obtained from the more northern parts 

 of these islands, which may be put in a concrete form by taking 

 Cidaria russata as an example. This insect is double-brooded 

 in the South of England, but it is probably single-brooded only 

 in the Hebrides. Now we find, in the genus Ephyra, that the 

 two seasonal broods of some of the species differ materially in 

 colour, but I am not aware that any one has pointed out any 

 difference between the two broods of C. russata. If such a 

 difference does exist, which form do the Hebridean insects most 

 resemble ? 



In the case of Pieris najn the two broods differ very much 

 in colour. I do not know how far the insect is found north, but 

 apparently it is not an inhabitant of the Shetlands, nor Outer 

 Hebrides ; it is important to know whether there is any part of 

 Scotland where it is single-brooded only, and wliether, when this 

 is the case, the specimens approach in colour to the alpine variety 

 P. hryonicB. 



' I am afraid our common insects are not sufficiently studied ; 

 Pieris napi, as Dr. Weisman has shown, is well worthy of 



