91 
6 CHaRLES PauL ALEXANDER 
The local species of Limnophila may be separated in accordance with 
the following key: 
If; 
2. 
3. 
Cell My of the wings present: 2325.25 .4.400 02.002. ee eee eee 2 
Cell Mi of. the wings lacking..3). 2.25056. . on ee cee eee 41 
A supernumerary cross-veinyin cell-R2.or in cell M... 2. = 35 eee 3 
No supernumerary cross-vein in cell 2 or in cell M........................-.-----. 6 
AVsupernumerary cross-vein: in celle see cans ee + 
A supernumerary cross-vein in cell R2 (Subgenus Dicranophragma O.S.) [Proc. Acad. 
Nat. Sci. Phila., p. 240. 1859.] (Plate XX XTX, 139.)....5...2.. L. fuscovaria O. S. 
Wings interruptedly crossbanded with brown; costal region without equidistant brown 
blotches; /?s spurred at the bend; antennae of male elongated. (Subgenus Idioptera 
Maeq.) [Mon. Dipt. N. Amer., part 4, p. 206. 1869.] (Plate XX XVIII, 115.) 
L. jasciolata O. S 
Wings hyaline or spotted with brown; Rs slightly or not at all spurred at the bend 
antennae of male short. (Subgenus ’Ephelia Schin.).....). 2a 
. Wings hyaline. [Proc. Acad. Nat. Sci. Phila., p. 591, pl. 25, fis. 2. 1914] (Plate 
XOX TBS) isi ee as a eee ne A ee 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, pl. 4, fig. 25. 1859.] (Plate XXXIX, 137.) 
L. aprilina O. S. 
6. Apical cells of wings pubescent; antennae of male elongated. (Subgenus Lasiomastix 
OLS.) ose oe Sl ae a eas oh eee ee 7 
Apical cells of wings not pubescent sué.e/n derujaa Ue Qeble S eile Stee ee ee 8 
7. Thorax shiny black; wings banded with brown. [Limnobia macrocera Say. Journ. 
10. 
11. 
Acad. Nat. Sci. Phila.., vol. 3; p- 20. 1823.] (Plate XX XVIII, 113.) 
L. macrocera (Say) 
Thorax dark gray; wings unmarked. [Mon. Dipt. N. Amer., part 4, p. 208. 1869.1. 
GPla te XeXexe VIET 7D) eae lee A eee L. tenuicornis 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 M:. 
There can be no doubt that L. tenuicornis and L. subtenuicornis should be coupled 
with L. macrocera in the subgenus Lasiomastiz, both being notable by the distinct 
pubescence in the apical cells of the wings.) 
- Thorax shiny black s..2 2055.3. God cis bales oe 8 2 ches eo ee ee eee 9 
Thorax not shiny black... .. 5.020605 34.3 ec. hiss ae es 20 oe eee 10 
. 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 O.S.) [Mon. Dipt. N. Amer., part 4, 
p. 226. 1869:]. (Plate: Xai; 144.) 0. 25.623. a er L. munda O. 8. 
Wings 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. Soe., vol. 24, p. 120-121, pl. 8, fig. 3. 1916.] ‘(Plate XL, 145.) 
L. pinninaies Alex. 
Hind tarsi white; antennae of male elongated..................-.-..--.-.-...---- 11 
Hind tarsi not whnte oe ee eee at oot a A ee 12 
Thorax black with a gray bloom; Ree about equal to or slightly longer than the basal# 
deflection of Cui. [Mon. Dipt. N. Amer., part 4, p. 209. 1869.] (Plate XX XVIII, 
Lib: Pee ety: PR A ener Mn ANNA tec sc.c.c fo ofc cz L. niveitarsis O. 8. 
Thorax reddish yellow; R2+; about twice as long as the basal deflection of Cu. [Ent. 
News, vol. 24, p. 248-249, fig. 1913.] (Plate XXXVIII, 119.)......Z. albipes Leon. 
