TEOPICAL AMERICAN DIPTERA OR TWO-WINGED FLIES 

 OF THE FAMILY DOLICHOPODIDAE FROM CENTRAL 

 AND SOUTH AMERICA 



By M. C. Van Duzee 



Of Buffalo, N. Y. 



The following paper is a report on three collections of Dojichopodi- 

 dae: one taken by J. M. Aldrich in Guatemala, during May and 

 June, 1926; one by C. T. Greene in the Panama Canal Zone, during 

 March and April, 1926; and the third by Nathan Banks in the 

 Panama Canal Zone, during June, July, and August, 1924. There 

 were a few specimens taken by others among the material studied. 



These collections contain 77 species, of which 61 are described as 

 new; there are two new genera. From the large proportion of 

 undescribed forms among them it would seem that there is much 

 work to do before we have even a good general knowledge of the 

 species inhabiting this interesting region. 



In using the measurements of tarsaj joints there must always be 

 an allowance made for individual variation and also the personal 

 equation, as no two persons seem to measure the joints with just 

 the same result when the measurements are made from pinned speci- 

 mens, but I think they will give the proportional length of the joints 

 much more accurately than any other method, unless the feet are 

 mounted on a slide. 



I wish to express my sincere thanks to Dr. J. M. Aldrich for the 

 privilege of studying the material from the United States National 

 Museum, and to Mr. Natlian Banks for sending me that from the 

 Museum of Comparative Zoology. 



Genus PSILOPUS Meigen 



Psilopus Meigen, Systematische Bcschieibung, vol. 4, 1824, p. 35. — Loew, 

 Smiths. Misc. Colls., No. 171, 1864, p. 229. — Aij)rich, Trana Amer. Ent. 

 Soc, vol. 30, September, 1904, pp. 279-286. — Van Duzee, Ent. News, vol. 

 26, January, 1915, pp. 17-26. 



No. 2755.— Proceedings U. S. National Museum, Vol. 74. Art. 10. 



2613—28— — 1 1 



