TRIFIDM. 25 r 



England, though occasional specimens from the South Coast 

 have the ground colour intensified to blue-black, the markings 

 remaining normal ; and one from Brighton, in Mr. Sydney- 

 Webb's collection, has the pure white colour very greatly 

 extended so that it becomes the ground colour of the fore 

 wings, with the transverse lines black and the cloudings dark 

 olive-grey. On the rocky coast of North Wales it becomes 

 darker, the white markings very much reduced in size and 

 more or less clouded with yellow, olive-yellow, or pale orange, 

 and an olive or orange tinge over the dark portions in varying 

 degrees until the white markings in some individuals wholly 

 disappear, partially suffused by the olive-brown ground colour, 

 partly becoming dingy olive-yellow. In the Isle of Man, on 

 the contrary, the white markings are very pure, the dark 

 ground almost blue-black, and there is a decided increase in 

 size. Very fine specimens are also found in Devon, and 

 there the tinge of orange or olive-yellow is often in some 

 degree assumed. In Scotland the size seems to be very 

 slightly reduced, the white markings are hardly so pure, or 

 are tinged with pale yellow, and the dark ground not so 

 intense, being in some degree tinged with olive ; on the North 

 East coast there is sometimes a general suffusion of olive- 

 yellow ; but it is in the Shetland Isles that the most extra- 

 ordinary forms are found — the white markings utterly 

 suppressed, or the stigmata alone white, or yellow, or pale 

 ochreous, or black-brown and only indicated by blacker 

 margins ; the sub-terminal line only indicated by its attend- 

 ant black clouds, and sometimes the whole surface of the fore 

 wings smoky-black or olive-black, with but a faint dappling 

 of blacker lines and crescents; on the other hand, some 

 specimens in these Islands are of the form in which the 

 ground colour is intensified, but the markings, though cur- 

 tailed, sharply white. This last form is also found in the 

 West of Ireland, and a specimen now before me from Sligo is 

 singularly rich in its deep dark colour and snowy blotches. 

 Specimens from the Hebrides are extremely beautiful, the 



