1916.] NATURAL SCIENCES OF PHILADELPHIA. 521 



face, a chitinized, median appendage directed caudad and slightly 

 ventrad, at the acute apex turned strongly dorsad. 



The Cognatella Group. 



Gonomyia < Gonomyia) flavibasis Alexander. 



Gonomyia flavibasis Alexander; Canadian Entomologist, vol. 48, pp. 317-319 

 (1916). 



A western species that is still known only from the type-locality, 

 Monterey County, California, July 18, 1896. 



The wing is shown on Plate XXVI, fig. 27. 



The male hypopygium (Plate XXX, figs. 76-78) with the pleurites 

 long and slender, the dorsal angle produced caudad as a flattened, 

 fleshy lobe that bears many hairs on the dorsal face; first pleural 

 appendage very long, flattened, the apex bent, the appendage with 

 many long, prominent hairs; second appendage complex, consisting 

 of a chitinized hook that is slightly bent; underneath the base of this 

 hook is a fleshy lobe with several short bristles on the outer face, 

 including two powerful bristles at the apex; above the base of the 

 hook is a slender, subchitinized rod that is darkened at the tip. 



Gonomyia iGonomyia) florens Alexander. 



Gonomyia florens Alexander; Canadian Entomologist, vol. 48, pp. 316, 317 

 (1916). 



A fly of cold Canadian conditions in the northeastern United 

 States: 



Maine, Penobscot County, Orono, July 12, 1913 (Alexander). 



New York, Fulton County, Sacandaga Park, June 18, 1916 (Alexan- 

 der); Gloversville, June 22, 1916 (Alexander); Herkimer County, 

 Indian Castle, June 9 to 13, 1915 (Alexander), the type-locality; 

 Tompkins County, McLean, June 5, 1916 (Alexander). 



The wing is shown on Plate XXVI, fig. 28. 



The male hypopygium (Plate XXIX, fig. 71) with the pleurites 

 very short and stout, the inner dorsal angle produced caudad into a 

 blunt fleshy lobe whose inner margin is fringed with numerous long 

 hairs; a short blunt, fleshy knob (A;) at the base of this lobe, provided 

 with five long hairs on the margin; first pleural appendage (i) slender, 

 originating just below the knob (k), directed proximad, the base 

 enlarged with two or three stout hairs, the tip slightly bifid, the 

 caudal arm with two bristles, the cephalic arm with one bristle; a 

 stout bristle just before the tip on the inner or cephalic side; second 

 pleural appendage (2) a powerful, chitinized hook, slightly curved, 

 directed proximad, bent strongly cephalad toward the apex; third 



