322 THE CANADIAN ENTOMOLOGIST 



Similar in colour to Gonomyia unicolor Alexander (Guatemala) 

 but larger, the mesonotum more grayish, pseudosutural fovea? 

 and tuberculate pits black, conspicuous, and the venational details 

 slightly different. 



Antenna' iniiformly dark brown throughout. Pronotal scu- 

 telluni light yellow. Mesonotal pnescuium grayish brown, 

 shiny, without apparent stripes; a rather light yellow area before 

 the pseudosutural fo\eir; a dull \ell()W area between this fo\ea' 

 and the transverse suture and a small \ellow spot on the sides 

 of the scutal lobes above the wing-root. Wing-venation: /?2+3 

 twice the length of R2 and much longer than Rs\ r-m nearly as long 

 as the basal dellection of Cu\, the latter inserted at from one- 

 quarter to one-third the length of cell 1st Ah. Male hypopygium 

 with the ninth tergite rather short, the caudal margin straight 

 or nearK so; ninth pleurite elongate, rather stout, the dorsal 

 pleural appendage rather short, cylindrical, Heshy, the cei)halic 

 or inner angle of the apex with two strong, powerful bristles, 

 the caudal or outer angle with two smaller hairs; second pleural 

 appendage strongly chitinized, the tip acute, curved; ventral 

 pleural appendage a long, pale lobe, subcylindrical, blunt at the 

 apex and bearing sparse elongate hairs; penis-guard very long and 

 pale, the apex bifid b\' a deep IT-shaped notch, each of the lobes 

 thus formed with long hairs; on the ventral face of this arises a 

 slender, rod-like median appendage, sparseh' short-hair\- at the 

 apex and down the \entral face; the di\ergent subtending arms 

 are slender, somewhat flattened, the apices produced into a slender 

 cylindrical point, the outer or \entral margin with a few sharp, 

 appressed teeth. 



Habitat — Mexico. 



Jlololype—d', Cordoba, Mexico; May 8, 1908 (Frederick 

 Knab). 



The type is in the United States National Museum. 



This species was earlier determined as being Gonomyia uni- 

 color, variety, (Proceedings of the United States National Museum, 

 vol. 44, p. 507, 1913); the differences between these closely allied 

 forms will be indicated in connecticn with the next species, 

 Gonomyia ivqualis, n. 



