916 Charles Paul Alexander 



The local species of Limnophila may be separated in accordance with 

 the following key: 



1. Cell Ml of the wings present 2 



Cell Ml of the wings lacking 41 



2. A supernumerary cross- vein in cell Ri or in cell M 3 



No supernumerary cross-vein in cell Ri or in cell M 6 



3. A supernumerary cross- vein in cell M 4 



A supernumerary cross- vein in cell Ri. (Subgenus Dicranophrogmn O.S.) [Proc. Acad. 



Nat. Sci. Phiia., p. 240. 1859.] (Plate XXXIX, 139.) L. fuscovaria O. S. 



4. Wings interruptedly crossbanded with brown; costal region without equidistant brown 



blotches; Rs spurred at the bend; antennae of male elongated. (Subgenus Idioptera 

 Macq.) [Mon. Dipt. N. Amer., part 4, p. 206. 1869.] (Plate XXXVIII, 115.) 



L. fasciolata 0. S. 



Wings hyaline or spotted with brown; Rs slightly or not at all spurred at the bend; 



antennae of male short. (Subgenus Ephelia Schin.) 5 



5. Wings hvaline. [Proc. Acad. Nat. Sci. Phila., p. 591, pi. 25, fig. 2. 1914.] (Plate 



XXXIX, 138.) L. johnsoni Alex. 



Wings spotted; a series of about 6 or 7 large brown blotches along the costal margin. 

 [Proc. Acad. Nat. Sci. Phila., p. 235, pi. 4, fig. 25. 1859.] (Plate XXXIX, 137.) 



L. aprilina 0. S. 



6. Apical cells of wings pubescent; antennae of male elongated. (Subgenus Lasiomastix 



0. S.) 7 



Apical cells of wings not pubescent 8 



7. Thorax shiny black; wings banded with brown. [Limnohia macrocera Say. Journ. 



Acad. Nat. Sci. Phila., vol. 3, p. 20. 1823.] (Plate XXXVIII, 113.) 



L. macrocera (Say) 

 Thorax dark gray; wings unmarked. [Mon. Dipt. N. Amer., part 4, p. 208. 1869.] 



(Plate XXXVIII, 117.) L. lenuicorrm O. S. 



(L. subtenuicornis Alex. [Can. Ent., vol. 50, p. 61-62, 1918], described since this 

 key was made, has cell Mi lacking. It is a member of the subgenus Lasiomastix and 

 is readily distinguished by the combination of pubescent wings and lack of cell Mi. 

 There can be no doubt that L. tenuicornis and L. subtenuicornis should be coupled 

 with L. macrocera in the subgenus Lasiomastix, both being notable by the distinct 

 pubescence in the apical cells of the wings.) 



8. Thorax shiny black 9 



Thorax not shiny black 10 



9. Wings with a brownish tinge; femora dull brownish yellow, narrowly tipped with dark 



brown; legs stout, conspicuously hairy; male hypopygium of the normal simple 

 limnophiline structure. (Subgenus Prionolabis 0. S.) [Mon. Dipt. N. Amer., part 4, 



p. 226. 1869.] (Plate XL, 144.) L. munda 0. S. 



Win?s hyaline or nearly so; femora dark brown, only the extreme bases paler; legs 

 slender, not conspicuously hairy; male hypopygium complex in structure. [Journ. 

 N. Y. Ent. Soc, vol. 24, p. 120-121, pi. 8, fig. 3. 1916.] (Plate XL, 145.) 



L. mundoides Alex. 



10. Hind tarsi white; antennae of male elongated 11 



Hind tarsi not white I'- 

 ll. Thorax black with a gray bloom; R2+3 about equal to or slightly longer than the basal 

 deflection of Cu,. [Mon. Dipt. N. Amer., part 4, p. 209. 1869.] (Plate XXXVIII, 



118.") L. niveiUirsis O. S. 



Thorax reddish yellow; 7^2+3 about twice as long as the basal deflection of Cui. [Ent. 

 News, vol. 24, p. 248-249, fig. 1913.] (Plate XXXVIII, 119.) L. albipes Leon. 



