TWO PECULIAR FORMS OF BOARMIA REPANDATA. 95 



In June, 1909, however, I bred about one hundred moths 

 from a captured wild female, and a good proportion — twenty-five 

 per cent. — of these had larger or smaller median areas of pearly 

 grey scales on both fore and hind wings. In extreme examples 

 the grey area occupies the whole of the central part of the 

 wings, and in others only a small part of the alar surface. All 

 the insects are symmetrical, and where the subterminal lines 

 c-ross the pale blotches they are somewhat lighter in colour and 

 can be clearly seen. The remainder of the wings, except the 

 scapulars, which are dull ochreous, are of a deep velvety black. 



The remaining part of the brood were var. 7iigm of an 

 unusually intense black, varying in the development of the 

 subterminal lines, from specimens in which these are brilliant 

 and complete to examples in which they are almost absent, 

 giving, as an extreme, an almost entirely black moth. 



Under the microscope the grey areas are seen to be fully 

 scaled, not, as one finds to be the case with the transparent 

 forms of Odontopera bidentata var. 7iigra, thinly scaled or with 

 the scales absent. The appearance of the insect is more 

 suggestive of the xanthism found in so-called bleached 

 Epinephelc ianira, and the varying size and amount of the pale 

 area further point to a case of parallelism. 



The peculiarity of these forms is not due to injury, as I have 

 examples showing undoubted injury which has resulted in a 

 clear, white, local patch which is not repeated on the other 

 wings, and, therefore, is not symmetrical. 



These xanthic varieties, if I may so call them, are fully up 

 to the average in size and development, in some cases above it, 

 and the true nigra forms, when very much dwarfed through the 

 race running out, do not show the peculiarity referred to in a 

 single instance. 



Cross pairings were obtained from black specimens of the 

 1909 brood, with the result that from a larger number of imagines 

 in June, 1910, only a few — some half dozen in all — of the 

 xanthic form were produced. 



It may be concluded, therefore, that as this variety is per- 

 manent and recurrent and found in a wild state, it is worthy a 

 varietal name, and I propose that of nigro-pallida to distinguish 

 it. The types, male and female, are in my collection. This 

 variety must not be confounded with the melanic white blotched 

 form, taken rarely in North Wales and Yorkshire, which has 

 large pale markings in the subterminal region on the fore wings 

 only, as normally occurs in typical specimens, and in which 

 there is a general pale irroration more or leas pronounced. 



Ochro-nigra, var. nov. 

 In July, 1910, I made various experimental crossings with 

 the object of discovering the possible parentage of var. nigro- 



