CHARLES P. ALEXANDER 235 



As indicated in earlier papers, bifasciata Fabricius is the same as 

 trifasciata Enderlein, the latter name being the correct one. T. 

 venezuelensis Macquart- is omitted from the key as I believe it to be 

 S3aionymous with T. melanocephala Fabricius, a variable species. 

 T. polita Osten Sacken is either an exceptionally small species or 

 else Osten Sacken's type is shrunken and no allowance was made 

 by him for this change in condition. The species identified by 

 Williston as complexa (Trans. Ent. Soc. Lond., 1896, 289) is not 

 this, but represents an apparently midescribed species that is 

 quite widely distributed in Middle America and the Antilles. 



A Key to the American Species of Teucholabis 

 Osten Sacken 



1. Wings spotted; oross-voin r-m obliterated by fusion. (Peru) 



paradoxa Alexander' 



Wings hyaline or banded, not spotted; cross-vein r-m present or lost 



Myatrophy 2 



2. Wings with the membrane hyaline or nearly so, unmarked except for 



the stigmal spot; in some species the membrane is slightly dark- 

 ened but in such cases the stigmal spot is darker, distinct 20 



Wings with the membrane clouded or banded, or with a seam along the 

 cord, or with the tip infumed or with the membrane darkened 

 and the stigma indistinct 3 



3. Wings with distinct bands 4 



Wings with the darker markings reduced to very narrow seams along 



the cord or to indistinct clouding at the ai)ex or else the whole 

 wing is uniformly dark brown 12 



4. Radial sector short, very arcuated, beginning opposite the tip of Sci 



[head dark brown above; pronotum yellow; thorax shiny black; 

 wings hyaline with a broad brown apex and brown markings 



along the cord.]. (Peru) munda Alexander* 



Radial sector longer, less arcuated, beginning far before the tip of 

 Sci 5 



5. Thoracic praescutum shiny black, unmarked 6 



Thoracic praescutum more or less orange-yellow or brownish 8 



6. Pronotum yellowish [head black; wings with the apical band includ- 



ing the distal end of cell 1st il/^; basal band broadly diamond- 

 shaped]. (Lesser Antilles, Colombia, French Cuiana.) 



trifasciata Enderlein* 

 = bifasciata Fabricius* 



■•' 1846. venezuelensis Macquart, Dipt. Exot., suppl. 1, 19, pi. 2, fig. 7 

 {Limnohia) . 



^ 1913. paradoxa Alexander, Ent. News, xxiv, 445, 440, pi. 16, fig. 8. 



■• 1913. munda Alexander, Ent. News, xxiv, 444, 445, pi. 16, fig. 7. 



' 1912. irifasciala Enderlein, Zool. Jahrb., xxxii, pt. 1, p. 69, 70, fig. Rl. 



* 1805. bifasciata Fabricius, Syst. Antl., 31 (Tipula) = trifasciata 

 Enderlein. 



TRANS. AM. ENT. SOC, XL. 



