A REVISION OF THE NORTH AMERICAN SPECIES OF 



THE DIPTEROUS GENUS NEURIGONA. 



(DOLICHOPODIDiE.) 



M. C. Van Duzee. 



The Dipterous genus Neurigona was established by Rondani 

 in Dipt. Ital. prodromus in 1856, with one species, quadrifasciata 

 Fabr., which is therefore the type of the genus. In 1829 

 Thomas Say described an American species as Medeterus 

 lateralis. Dr. Loew in 1864 pubhshed three others, dimidiata, 

 rubella, and tenuis, and in 1869 a fourth, carbonifer. In 1899 

 W. M. Wheeler added two more, floridida and lienosa, thus 

 giving us seven described species from America north of Mexico. 

 From farther south Prof. Aldrich has described decora and 

 signijer from Grenada and St. Vincent, and J. R. Schiner has 

 given us brasilie?tsis from Brazil. These are all the species 

 previously described from America so far as I can learn. 



The genus Neurigona as characterized by Dr. Loew under 

 the name Saucropus in his Monograph of the Dolichopodidae of 

 North America are: 



"First joint of the antennae without hair on the upper side; arista 

 dorsal ; thorax with a sloping area upon the middle of its posterior end ; 

 feet very long and slender; hind tibia? elongated, the first joint of hind 

 tarsi without bristles, shorter than the second; abdomen elongated and 

 narrow, especially in the male; hypopygium disengaged, short and stout, 

 inflected, with short very little developed appendages; color of the 

 body principally or at least partially yellow; hairs and bristles mostly 

 black. " 



The above characters serve to define the genus as I use it in 

 the present paper but there are some exceptions that should be 

 noted. The bristles of the dorsum of the thorax are always 

 black, thus separating the species of this genus from those of 

 the genus Chrysotimus where they are yellow, but those of the 

 abdomen are often pale as are also the hairs especially in the 

 male. There is a group of western species which are entirely or 

 almost entirely blackish; the first joint of the hind tarsi is 

 sometimes longer than the second, as is the case in siiperbiens 

 Loew, which is synonymous with lateralis Say, and fully as 

 long in the male of tenuis Loew, also longer in australis n. sp. 



In the table of genera of the Dolichopodidae in Williston's 

 Manual of the North American Diptera under No. 28 we have 

 to take fourth vein converging towards the third in order to 



