528 PROCEEDn'GS OF THE NATIOyAL MDSEVM. vol. 44. 



KEY TO THE SPECIES OP POLYMEBA— Continued. 



10. Thorax light-colored; brownish-yellow with a narrow dark pleural stripe; wings 



brown albitarsis Williston ' (Le-sser Antilles). 



Thorax uniform in color, dark brown; wings gray -.i^orocica, new species (Brazil). 



11. Large species; length (male) 4.5 mm.; wing 4.7 mm.; distance of Ki beyond r 

 equal to that space between Scj and r; wings yellowish. 



inomata, new species (Brit. Guiana). 

 Small species; length (male) 3 mm.; wing 4.6 mm.; distance of R, beyond r 

 much less than that space between Scj and r; wings gray. 



grisea, new species (Panama). 

 (Probably here; see description.) 



POLYMERA PLEHRALIS, new species. 



Size medium; flagellar segments of the antennse tri-nodose; wing 

 vnth. cell Mj absent; Mj-t-Cui much shorter than Mj alone; tarsi 

 white or whitish; thoracic pleura3 wdth a broad black stripe. 



Length, male, 5 mm.; female (to tip of ovipositor), 6.6-6.8 mm.; 

 wing, male, 6.4 mm.; female, 6.2-6.8 mm.; antennae, male (about), 

 8.5 rmn.; hind leg, female, femur, 5.4 mm.; tibia -j- tarsus, 8.6 mm. 



Male. — Palpi and rostrum light brown, the latter more 3-ellowish; 

 eyes large, conspicuous, leaving the vertex narrow between tlae eyes; 

 vertex grayish; occiput broMTiish-gray. Antennas, basal segment 

 dark brown, second lighter browTi, tlm-d elongate-cj-luidrical fifth 

 to near the end (most noticeable in the region of the tenth segment) 

 constricted twice, producing a tri-nodose effect, segments brown, the 

 extreme base and tip paler, yellowish, giving an annulated appear- 

 ance to the antennte. 



Thorax: doi-sum uniform light brown; pleurae very broadly dark 

 brownish-black, extending from the cer\ncal sclerites to the abdomen, 

 this color encroaching on the fore coxa; sterna pale wliitish-yeUow. 

 Haltercs light browTi, the knob rather dark. Legs: coxee, trochan- 

 ters and extreme base of the femora pale whitish-yeUow, remainder 

 of the femora and the tibise pale brown, darker at the extreme tip; 

 tarsi yeUo^visll-white, except the last segment, wliich is brown. 



Wings: uniformly tinged mth light brown. Venation: Sc rather 

 long, ending about opposite the fork of R2+3; Rs not gently arcuated 

 at its basis, but rather square; Ri be3-ond the cross-vem r about two- 

 fifths the distance from Sc, to r; R2+3 short, shorter than the basal 

 deflection of Cuj; basal deflection of R^+j longer than r-m. Mi+, 

 fused to the wing-margin. Ma-fCu, short, only about two-fifths as 

 long as Cu, be3-ond the fork. (See iig. 17.) 



Abdomen blackish, sternum Uttlc, if anj', paler. 



Female. — Quite similar to the male, but antennae short, normal in 

 appearance, not annulated; if bent backward, would extend about 

 to the base of the abdomen. In color and venation, as in the male. 



' Trans. Ent. Soc. Lond.. 1S96, p. 296, pi. 10, fig. 71. 



