No. 64] DirTERA or coxxecttcut: taxoxomy 405 



Siibfrenus Limnophila Macquart 



The .subgenus LimnophUa^ as here restricted, inchules only six lo- 

 cal specie^ forminof a very loose agj^refration. Of these species, albipcs 

 and niveitarsis form one <>:roiip, but tlie i-eniaininji; si)ecies are so dif- 

 ferent among- themselves that it is difficult to point out relationships. 

 It is pi-obable that the only local species that is strictly consubgeneric 

 with the genotype of L'nnnopkHa is irforafa Johnson. The adult 

 flies of aJhipes and niveitarsis may be swept from rank vegetation in 

 shaded gorges and along minor mountain streams; laricicola and 

 poefica are characteristic bog-inhabiting species; hrevifurca frequents 

 wet places in woods, alder swam])s. and similar situations; irrorafa 

 inhabits the southern gum swamps, where it i-ests on the rich marsh 

 vegetation. Although nothing conclusive seems to be known con- 

 cerning the subject, it seems highly probable that the early stages of 

 all of the included species above mentioned will be found to occur in 

 rich organic earth in and near the hannts of the adult flies. 



Key to Species 



1. Wings yellowish subhyaline, with an abundant irrorate brown pattern that 



includes small, transverse, brown dashes in all the cells ; legs yellow, the 



tips of the femora and tibiae abruptly blackened irrorata 



Wings unmarked, except for the stigmal cloud, and, in cases (poefica). re- 

 stricted clouds at origin of Rs and along tlie cord ; femora and tibiae not 

 abruptly tipped with black 2 



2. Wings with cell il/i very small, from one-third to one- fourth the length of 



its petiole (Fig. 44, D) brevifurca 



Wings with cell il/i of normal size, subcqual in length to. or only a trifle 

 shorter than, its petiole (Fig. 44, C, E) 3 



3. Posterior tarsi extensively snowy-white 4 



Posterior tarsi not whitened, similar in color to the other tarsi 5 



4. General coloration of thorax shiny reddish yellow to brown, the mesonotum 



sometimes more infuscated medially ; pleura clearer yellow ; Sc short, end- 

 ing about opposite two-thirds to three-fourths the length of Rs (Fig. 44, C) 



albipes 



General coloration of thorax black, heavily gray pruinose; Sc longer, ending 

 about opposite the fork of Rs _ niveitarsis 



5. Wings unmarked, except for the darker stigmal area; Rs relatively shcirt. 



less than two times the length of ))i-cu. angulated but not spurred at origin: 



ground-color of head gray iancicola 



Wings with faint dark clouds along cord and at ongni of Rs; Rs long, more 

 than twice the length of iii-cii. angulated and usually spurred at origui 

 (Fig. 44. E) : ground-color of head yellow to brownish yellow poetica 



Limnophila {Limnophila) albipes Leond. (Figs. 44, C; 45, O). 

 1913. Lfmnophila albipes Leonard; P:^nt. News, 24:248-249. 



Figs.— Leonard. Ibid., 24:248, text-figure (wing) : 1913. Alexander. Cfls. N. Y.. 

 1, pi. 38, f^g. 119 (wing) ; 1919. 



Body not or scarcely pruinose. Antennae ( $ ) elongate, approxi- 

 mately one-half as long as body, of 9 shorter, extending to base of 

 abdomen. Femora obscure yellow, the tips weakly darkened: tibiae 

 and tarsi brown, the po.sterior tarsi snowy-white. Wings (Fig. 44, C) 

 subhyaline, the stigma a little darker: Sc. at tip of Sd; /f2+M + 4 long, 

 nearlv twice the length of m-cu^ the latter at or beyond nndlengrth of 

 cell isf M., Abdominal tergites dark brown, the sternites paler, in 



