150 



THE YOUNG NATURALIST. 



ON THE VARIATION OF SPECIES. 



By C. W. DALE. 



(Continued from page 127 J 



Before proceeding further, I must correct a mistake in reference to Satyrus 

 janira, " of which white and light-brown varieties occur in the north of Eng- 

 land/' should be south of England. 



The richest and darkest specimens of Satyrus- janira I know occur in the 

 Isle of Harris. The Shetland Isles, the Outer Hebrides, and the Isle of Port- 

 land, furnish us with three splendid illustrations of local variation in Hepia- 

 lus humuli var. Het/dandica of Staudinger, Boarmia repandaria var. Sodo- 

 reusium of Weir, and Eudorea mercurietta var. Portlandica of Dale. This 

 latter, which was for a considerable time, considered to be identical with the 

 E. plimoleuca of Zeller, is subject to considerable variation, some specimens 

 departing from the normal dark coloration of that species as found in other 

 parts of England, to a pure white with a broad slaty grey band across the 

 upper wings. Turning to the order Coleoptera, we find that Nebria compla- 

 nata, Linn., assumes a more pallid hue in the neighbourhood of Bordeaux, 

 than it does on the sandy coasts of Devonshire and Wales ; and it is well 

 known that examples of Pelophila borealis, Payh, from Killarney and Lough 

 Neagh are permanently larger, and much more metallic, than those from the 

 Orkneys. In Lundy Isle there is a Psylloides luridipennis, Kute, found in 

 abundance on A. brassica, along the ascent from the eastern landing place, 

 which varies " in every consecutive shade, between the limits of light yellow 

 and dark metallic green, the former of which state (the normal one on that 

 rock), might have been fairly set down as specifically distinct from the latter, 

 did not observation on the spot decide the question for us without doubt/' — 

 See Wallaston on " Yariation of Species, page 61. 



The Carabus exasperatus of Curtis, which is found in Portland and other 

 parts of Dorsetshire, is only a local variety of Carabus violaceus of Linnseus. 

 Anomala Frischii, Fab j possesses a green variety Julii, which occurs at Lul- 

 worth. Nebria brevicollis has a broad thorax on the low ground at Amble- 

 side, and a narrow one on high ground. In Portland also it has a narrow 

 thorax. The Leistus montanus, Steph., again, is a mountain variety of Zeis- 

 tusfulvibarbis. Most species of Coleoptera are of a more pallid hue when 

 occurring on the sandy shores of the sea, than they are when occurring 

 inland. 



Mr. Bates, in his interesting and valuable work, " The Naturalist on the 

 Eiver Amazon/' tells us he has discovered intermediate forms to exist be- 



