1916.] NATURAL SCIENCES OF PHILADELPHIA. 513 



18. Male hypopygium with the dorsal pleural appendage armed 



with a chitinized hook 19 



Male hypopygium with the dorsal pleural appendage without a 

 hook, although with two powerful bristles at the tip 20 



19. Male hypopygium with the dorsal appendage two lobed, the 



caudal arm a powerful chitinized spine; ventral arm with a 

 sharp, chitinized, feebly curved spine. (Eastern United 



States.) subcinerea Osten Sacken. 



Male hypopygium with the dorsal appendage irregular, not two 

 lobed, the outer face near the apex with a strong, curved, 



chitinized hook. (Extra-limital; Guatemala.) 



cequalis Alexander. 



20. Male hypopygium with the ventral appendage prominent, 



directed caudad, narrowed at the base, the apex a slight 

 chitinized tooth directed proximad. (Western United States.) 



virgata Doane. 

 Male hypopygium not as described 21 



21. Male hypopygium with the ventral appendage a double, dark- 



colored lobe, the inner arm stout-cylindrical; the outer arm 

 slender, curved, bearing at the tip two divergent hairs; penis- 

 guard subtended by two divergent chitinized arms that are 



acute at their tips. (Extra-limital; Guatemala.) 



unicolor Alexander. 

 Male hypopygium with the ventral appendage pale, not 

 chitinized; penis-guard long and pale, the apex bifid by a 

 deep U-shaped notch; the divergent subtending arms are 

 slender, the ventral margin with a few sharp, appressed teeth. 

 (Extra-limital; Mexico.) mexicana Alexander. 



Subgenus LEIPONEURA Skuse. 



The Cinerea Group. 



Gonomyia (Leiponeura) alexanderi Johnson. 



EUiptera alexanderi Johnson: Psyche, vol. 19, p. 3, fig. 6 (1912). 



This handsome little fly is locally common. Its known distribu- 

 tion over the eastern United States is as follows: 



New York, Fulton County, Sport Island, Sacandaga River, June 

 11, 1914, to August 24, 1910 (Alexander), the type-locality; Herkimer 

 County, Indian Castle, June 13, 1915 (Alexander). 



North Carolina, Buncombe County, Black Mountains, June 13, 

 1912 (Beutenmuller). 



A female specimen from Piano, Collin County, Texas, in August 

 (E. S. Tucker), probably belongs here, but may possibly represent 

 G. helophila Alexander. This is also the species mentioned by 

 Osten Sacken in the Monographs, part 4, p. 179, without locality. 



The wing is shown on Plate XXVI, fig. 17. 



