1921] NATURAL SCIENCES OF PHILADELPHIA. 61 



length, the outer appendage more slender, at the tip split into two 

 short, subequal points. 



Habitat. — Peru. 



Holotype, d", Napo River, June 8, 1920 (H. S. Parish). 



Paratopotype, c^. 



Elephantomyia supernumeraria is distinguished from all the de- 

 scribed American species of the genus by the heavily patterned wings 

 and from all known species of the genus hy the presence of a super- 

 numerary cross vein in cell Rz of the wings. 



CTENOLIMNOPHILA gen. n. 



Antennae with sixteen segments, the flagellar segments short- 

 cylindrical. Tibiae provided with spurs. Wings with Sc^ at the 

 tip of Scx; a supernumerary crossvein in cell R^; cell 1st ilf 2 very 

 long and narrow, irregular in outline, approximately twice as long 

 as the cells beyond it; cell Mi lacking. Male hypopygium with 

 the outer pleural appendage provided Avith very long, appressed 

 teeth on the outer face before the tip. 



Genotype.- — Ctenolimnophila hivena, sp. n. (Amazonian Region). 



The general appearance of the two species now known to belong 

 to this genus is much more like a Gnophomyia than a Limnophiline 

 form. Gnophomyia decisa Alexander, described from imperfect ma- 

 terial, is now known to be a member of this genus. The tibial spurs 

 in C. decisa are much shorter and stouter than in C. hivena. The 

 type of hypopygium is strongly suggestive of Ephelia and Atarba. 



Ctenolimnophila bivena sp. n. 



Male.- — Length 4.5 mm.; wing 4.8-5.3 mm. 



Generally similar to C. decisa but differing in several important 

 details. The general coloration is dark brown, the legs conspicu- 

 ously light yellow. The hairs of the legs are longer and more out- 

 spreading than in decisa. The principal chfferences between the 

 two forms are found in the wings, as follows: 



Wings with a supernumerary crossvein in cell Rz in addition to 

 the one in cell /?;, the former lying a short distance proximad of 

 the latter. Wings more uniformly darkened, the radial cells uni- 

 formly dark brown, the cubital and anal cells grayish brown; narrow^ 

 seams and spots at the origin of Rs, along the cord, outer end of 

 cell 1st Mi and the supernumerary crossveins darker brown; no in- 

 dications of the three pale spots along the costal margin as in decisa; 

 the only pale areas on the wing are the centers of cells 1st Mi, 2nd 

 Mi, Ms and a faint wash before the cord in the end of cell R. 



Habitat. — Peru, Brazil. 



Holotype, d", Napo River, Peru, June 22, 1920 (H. S. Parish). 

 Paratopotype, d^ ; paratype, sex?, Teffe, Brazil, December 24, 

 1919 (H. S. Parish). 



