216 ENTOMOLOGICAL SOCIETY 



gulate near base on costal margin, thence rapidly tapering to slender tip. 

 Length 3 mm. 



From Potomac river near the Long Bridge, 25th August. 

 Orthotrichia americana Banks. 



From Washington, latter part of May till middle of August. 

 Oxyethira dorsalis, n. sp. 



When at rest it is blackish, with a median dorsal white stripe formed by 

 the white hairs of head, middle of thorax, the basal part of hind margin 

 of fore wings, and the white fringe of hind margin. The antennae are 

 white, with a few dark spots before tip, the vertex with two rosettes of 

 white hair; the thorax has white hair on the middle, dark on the sides; 

 the fore wings are clothed with dark brown hair, with the apex and the 

 basal part of radius jet black; before the middle there is a white spot on 

 each margin, sometimes apparently connected, beyond these is a white 

 patch in the middle of wing, and farther out are two white patches on 

 each margin, the last just before the black upturned tip. The fringe of 

 the fore wing is rather long on the costal margin, and before tip it is 

 much longer than the width of the wing at that point ; the fringe of hind 

 margin is much longer, especially toward tip. The hind wings are gray, 

 with darker veins, and dark costal fringe, the gray hind fringe more than 

 three times as long as width of wing. The fore wings are very slender, 

 the costal margin before the tip is slightly concave, the tip almost sharp; 

 the hind wings are very slender, acuminate, the costal margin near base 

 swollen. Legs yellowish ; spurs 1-3-4; hind tibiae with long fringe, true 

 hind spurs also very long. Length 3 mm. 



Many specimens from Washington, D. C., Falls Church, Va., 

 and Plummer's Island, Md. ; June to September. 



This species is separated from Orthotrichia americana, which 

 it superficially resembles, by the fact that the costal fringe of fore 

 wings near tip is longer than the width of the wings at that place, 

 while in the latter species the fringe is barely longer than else 

 where along the costal margin. 



EXPLANATION OF PLATE II. 



1. Protoptila maculata. 10. Psocus bisignatits. 



2. Orthotrichia pallida. 11. Cyrnus pallidus. 



3. Psocus elegans. 12. Helicopsyche annulicornis 



4. Leptocerus flavus. 13. Protoptila maculata. 



5. Oxyethira dorsalis. 14. Lepidostoma togata. 



6. Hydropsyche speciosa. 15. Lepidostoma togata. 



7. Orthotrichia pallida. 16. Protoptila maculata, 



8. Allotrichia signata: 17. Allotrichia signata. 



9. Cyrnus pallidus. iS. Psocus bisignatus. 



