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fainter and then obsolete, and, curiously enough, it is buff-coloured 

 in all the specimens that possess it. This is the median oblique 

 line which, commencing at the orbicular, ends a little way above the 

 outer angle of the fore-wings. This line is so prominent that were it 

 not for the intermediates, in which one can trace its gradual suppres- 

 sion, it might be thought that it was sufficient to mark the limits of 

 a species. It will be noticed that the grey specimens more quickly 

 tend to become unicolorous ; and in these toned examples, so to 

 speak, it is the grey and not the black that predominates. I have 

 only one good example of a melanic form ; in regard to this one it 

 is scarcely beside the mark to repeat a former statement made at 

 this Society — that the atmosphere in the Indian Territory is excep- 

 tionally moist, the average barometric reading for many consecutive 

 weeks being 28*8, with no great extremes even when violent atmo- 

 spheric changes occurred. 



