LITHOSID^. 



207 



appears to be most strictly confined to the extreme edge of 

 the coast, though one specimen — which surely must have been 

 migrating — was taken by Mr. F. Norgate in Foxley Wood, 

 Norfolk. It is common at Dover, Kent, and in the Isle of 

 Wight, at the edge of the cliffs, and at Shoreham, Sussex, on 

 the beach. Also found at Folkestone, Hastings, and elsewhere 

 on the coast of Kent and Sussex, and rarely in Devonshire ; 

 in the Isle of Man ; and on the Island of Ramsey, near St. 

 David's, South Wales. Some years ago it was found in plenty 

 on the lighthouse beach near Aldeburgh, Suffolk, and lai-vge 

 were found there commonly, but from some unexjDlained cause 

 it seems to have disappeared. In Scotland it is recorded as 

 having occurred at Crieff, Clydesdale, and in Aberdeenshire. 

 Dr. F. B. White says: "Tweed, Tay, Clyde, and Argyle 

 districts." In Ireland it is common in the rough limestone 

 district of Gal way. Abroad it appears to be rather a moun- 

 tain, than a coast, species, and is found in Northern and 

 Central Europe, esisecially in the Alps (at high altitudes 

 producing local variations), as well as in Dalmatia, Siberia, 

 and Asia Minor. 



2. S. mesomella, L. — Expanse, male \\ inch, female 1 

 inch. Fore wings broad, rather squared, pearly-white or 

 yellowish, with two black dots ; hind wings grey. 



Antennae threadlike, with rows of minute bristles in the 

 male, whitish above, dark grey beneath ; head and front of 

 the thorax yellow, back of the thorax silvery- white ; abdomen 

 slender, pale grey, shading into yellow at the hinder ex- 

 tremity. Fore wings broad, costa regularly arched, apex 

 blunt and squared, hind margin rather straight and hardly 

 oblique ; dorsal margin almost straight from near the base ; 

 costa beyond the middle very slightly rolled back ; opaque, 

 pearly- white, or silvery greyish- white, rather shinino-; 

 costal and hind margins yellow, shaded into the white sur- 

 face; on the costa near the middle is a black dot, and 

 opposite to it, near the dorsal margin, another; cilia yellow. 



