SEPTEMBER THORN. 273 



Dusky Thorn (Efi?iomos fusca?itarid). 



Figs. 36,4$, Plate iii, represent the usual form of this 

 species ; in some specimens the outer marginal pale purplish- 

 brown shading spreads inwards over the fore wings to the base ; 

 in other examples it is only seen on the upper part of the outer 

 area. 



The caterpillar (Plate no, Fig. 3) is green, pretty much of 

 the same tint as the underside of the ash leaf upon which, and 

 the stalks, it rests by day. In some examples the general colour 

 inclines to pale brown, or reddish brown. It may be found 

 during the summer, and where the leaves are seen to have 

 neat round holes in them, these should be examined, when this 

 caterpillar will probably be found somewhere adjacent. Ash 

 {Fraxinus excelsior) is the usual food, but possibly privet 

 might answer as a substitute. The moth is out in August and 

 September, and occurs in most parts of Southern England 

 where the ash flourishes ; its range extends into South Wales, 

 and northwards to Durham and Northumberland. Only 

 doubtfully recorded from Ireland, and apparently unknown in 

 Scotland. 



September Thorn {Ennomos erosa?'ia). 



This species, shown on Plate 134, Fig. 6, varies in ground 

 colour from pale ochreous to pale fulvous ; the cross lines 

 approach towards the inner margin, and sometimes the second 

 line is bent inwards below the middle. The central spot is 

 generally absent, and when present is exceedingly faint. The 

 twig-like caterpillar is brownish, with a greenish or purplish 

 tinge. In its infancy it is a smooth-looking creature, but as 

 it advances in growth knobs and humps appear, the most 

 prominent of which are on rings 2, 5, 8, and 11 ; on the 



Series IL T 



