THE CANADIAN ENTOMOLOGIST 139 



Expanse: 5-6 mm. 



Nine specimens, Lancaster, Ohio, bred from mines on leaves 

 of huckleberry, Gaylussacia haccata (Wang.) Koch. The mine is 

 of the usual character in the genus, starting as a narrow linear 

 mine which abruptly enlarges into a semitransparent blotch (10 

 by 3 or 4 mm.). The elliptical case is attached as usual by a 

 silken band to a leaf or twig. Mines which were collected August 

 21, 1914, produced imagos May 10-17 of the following year. 



This is the largest species of the genus thus far described. 

 Apart from its size, it may be distinguished from other species 

 chiefly by the pale basal half of the fore wings and the fact that 

 the dark dorsal patch never extends nearer the costa than the apex 

 of the dors'al silvery spot, and therefore the ground colour extends 

 without interruption between the silvery spots to the termea 

 beneath the apical spot. 



It is most closely related, particularly in character of mine 

 and shape of pupal case, to C. ostrycsfoliella Clem., of which there 

 seems to be no published description. To supply this the following 

 brief description of C. ostrycsfoliella is given. 



Coptodisca ostryaefoliella Clemens. 



Antennae fuscous; head with other appendages pale silvery 

 gray. 



Thorax and fore wings in the basal half pale silvery gray; 

 apical half of fore wings yellow. At the apical third is a triangular 

 silvery white spot dark margined on both sides. A little anterior 

 on the dorsal margin, a similar but smaller and shorter spot narrowly 

 separated from the costal spot by the ground colour or by the 

 costal-wards and proximal extension of the dark dorsal patch lying, 

 beyond the dorsal white spot. This dark patch extends nearly 

 or quite to the apical fan-shaped black spot, which is preceded 

 and edged as usual by one or two silvery scales, and from which 

 the usual black pencil extends outward into the cilia, which are 

 whitish. Preceding the apex in the costal cilia is an almost perpen- 

 dicular streak of black scales. Hind wings pale gray. 



Abdomen gray above, silvery beneath. Legs silvery with 

 dark fuscous tarsi. 



Expanse: 4-4.2 mm. 



