THE CANADIAN ENTOMOLOGIST. 107 



Thorax black, with a few scales at its posterior end, and at the 

 tip of the patagia white. Fore wings black; base white with a 

 faint yellow tinge; a slightly curved narrow white fascia at 2-5, 

 about equally distant from the base on either margin; at 4-5, a 

 triangular white costal spot, whose inner edge is almost on a line 

 with the inner edge of a similar dorsal spot, placed a little nearer 

 the base. Cilia around the apex white, elsew^here concolorous 

 with wing. 



Legs black, silvery on their inner sides, tarsal segments tipped 

 with white. Hind tibiae with a spot in the middle and the apex 

 conspicuously white. 



Expanse: 6.5-7.5 mm. 



Eight specimens, Cincinnati, O., August 2-8. 



Occasionally, especially in males, the fascia and pair of spots 

 are ^■ery, narrow, but still distinctly defined. 



The larva is a miner in leaves of Hystrix patiila Moench., a 

 common tall grass in dry hillside woods. The mine starts as a 

 narrow line, scarcely visible on the upper side, and gradually 

 enlarges into a blotch, wn'th its greatest width 4 or 5 mm. Except 

 in the wider portions of the blotch, the parenchyma near the 

 lower side only is consumed; even in the broadest part of the blotch 

 some of the parenchyma near the upper epidermis is left, giving 

 the mine- a speckled and greener appearance on the upper side, 

 so that the mine is more distinctly visible on the lower surface 

 where the epidermis is whitish. Pupa enclosed in a few criss-cross 

 silken threads. At the time the larvae were collected, July 18^ 

 many of the mines were deserted. 



Theisoa constrictella Zeller, 



Oecophora constrictella Zeller, Verh. zool.-bot. Ges. Wien^ 

 XXIII, 291, 1873. 



Theisoa constrictella, Dyar, List N. A. Lep., No. 6130, 1902. 



The larva feeds under a web on the lower surface of leaves of 

 white elm (Ulmus americana L.) and cork elm {Ulmiis racemosa 

 Thom&s). A whitish silken tube crosses from the base of the 

 petiole to the underside of the leaf, but is not attached to the 

 petiole except at the base. From the mouth of this tube a thin 

 web spreads over the basal part of the leaf; gradually covering 

 more and more of the breadth of the leaf as the tube is lengthened. 



