Insects. 



8303 



My excellent friend, Mr. Henry Doubleday, having sent me, for 

 the present work, a series of Lithosia from Great Britain, 1 found, 

 among his specimens of L. com plana, two which appeared to me spe- 

 cifically different ; these had been found in a bog near Warrington, 

 in Cheshire. At my request Mr. Doubleday pressed his correspond- 

 ent to search for the caterpillar, and for additional specimens of the 

 perfect insect. On the first point the search was fruitless ; but a large 

 number of the perfect insect were obtained, and I have now before me 

 a score of specimens, all of which present the same characters, and 

 confirm me in the opinion that this species is probably distinct 

 from L. complana. Nevertheless, the question cannot be finally de- 

 cided until the discovery of the prior states. 



L. molybdeola is intermediate between L. complana and L. plum- 

 beola ; it has the figure of the former, the colour of the latter, and is 

 rather more shining than either. It may be distinguished from L. 

 complana by its darker hue, and in having the yellow costal stripe 

 straighter, and terminating in a point before arriving at the apex as 

 in L. plumbeola. The hind wings are always strongly tinged with 

 gray along the inner margin, this colour even extending, in some spe- 

 cimens, over the whole surface, and leaving none of the usual 

 ochreous colour visible, except a tolerably broad border, which forms 

 a notch between the median and internal nervures. The head and 

 neck are of a very bright yellow ; the thorax and abdomen lead- 

 coloured, this last not exhibiting any yellow except at the extremity, 

 and the yellow even here is generally mixed with gray. The female 

 especially has scarcely any yellow at the anus ; it is of the size of the 

 male, or smaller. 



This species may be still more readily distinguished from L. plum- 

 beola by the form of the wings, which altogether resemble those of 

 L. complana ; the gray is equally shining, the costal band straighter 

 and more distinct, the cilia tinged with gray, the neck unicolorous, 

 the hind wings lead-coloured, but especially by the presence of the 

 scaly fold of the costa of the fore wings. 



L. molybdeola varies much more than L. complana. It inhabits 

 low and marshy places, and its larva in all probability feeds on the 

 lichens which grow on the stems of the heath, or which carpet the 

 stones that are scattered over the surface of the ground. There is no 

 doubt that, if sought in similar situations to those in which it occurs 

 in the North of England, it would be found in France and other 

 countries of Europe. 



VOL. XXI. 



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