918 Charles Paul Alexander 



23. Large, wing of female 21.5 mm.; thoracic dorsum reddish brown with three velvety. 



brown stripes, the middle one narrowly split by a line of the ground color; ground 

 color of wings yellowish and brown; basal abdominal tergitos yellow without prominent 

 setigerous punctures; cross-vein r close to the tip of R\. 'Proc. Boston Soc. \at. 

 Hist., vol. 34. p. 12G-127, pi. 1(), fig. 18. 1909.] (Plate XXXIX, 140.). . . L. nlleni Johns. 

 Smaller, wing of female 20 nmi. ; thoracic dorsum gray with three narrow velvety-brown 

 stripes, the middle one split by a broad pale line; ground color of wings hyaline; basal 

 abdominal tergites gray with prominent setigerous punctures; cross-vein r more 

 distant from the tip of Ru [Journ. N. Y. Ent. Soc, vol. 24, p. 118-120, pi. S, fig. 2. 

 1916.] (Plate XXXIX, 141.) : L. marchandi Alex. 



24. R2+S very elongated, nearly twice the length of R2 alone; cross-vein r on Ri^s. [Proc. 



Acad. Nat. Sci. Phila., p. 238, pi. 4, fig. 26. 1859.] (Plate XXXVIII, 127.) 



L. ultima O. S. 

 (L. rdlima is included in both sections of couplet 12 because the character of the 

 position of the cross-vein r is slightly variable and there is a possibility of mis- 

 interpretation.) 

 Ri+3 shorter, not longer than R2 alone; cross-vein r on R2 25 



25. Basal deflection of Cui at the inner end of cell 1st M:. (Subgenus Dadylolabis 0. S.) . .26 

 Basal deflection of Ciii near the middle of cell 1st M2 27 



26. Wings spotted with brown. [Proc. Acad. Nat. Sci. Phila., p. 240, pi. 3, figs. 28, 28a. 



1859.] (Plate XL, 148.) L. montana O. S. 



Wings unspotted. [Mon. Dipt. N. Amer., part 4, p. 229. 1869.] (Plate XL, 147.) 



L. cubitalis O. S. 



27. Wings spotted with brown or distinctly seamed along the cross-veins and deflections of 



veins 28 



Wings clear, or with only the stigmal spot (in L. poetica with a tiny cloud at the origin 

 of Rs and the basal deflection of Ri-\-;.) 35 



28. Wings heavily irrorate with brown over the entire surface. [Proc. Boston Soc. Nat. Mist., 



vol. 34, p. 127-128, pi. 16, fig. 17. 1909.] (Plate XXXIX, 133.) . . . L. irrorafa Johns. 



Wings not heavily irrorate over the entire surface, the markings appearing as broad 



seams to the veins or as dark tips to the wings 29 



29. R2+3 short or very short, much less than R2 alone; cross-vein r at about midlength of 



R2; petiole of cell Mi longer than or subequal to this cell; brown seams to the veins 



more extensive ; antennae of male short 30 



R2+1 very long, subequal to R2 alone; cross-vein r just beyond the fork of Ri+s; petiole 

 of cell Ml distinctly shorter than this cell; brown seams on the wings limited to r-m 

 and the deflection of 724+5; antennae of male elongated. [Mon. Dipt. N. Amer., 

 part 4, p. 205. 1869.] (Plate XXXVIII, 114.) L. unica O. S. 



30. Radial sector short, arcuated to almost square at its origin; cross- vein r situated at 



[about midlength of vein R2, which is oblique; outer end of cell 7?2 very broad due 

 to the oblique nature of vein i?-; species with the cross-veins seamed with brown have 



the tip of the wings more or less infuscated. (Subgenus Phylidorea Bigot.) 31 



Radial sector longer; vein R2 not oblique and the cell 7?2 not strikingly broadened at 

 its apex; broad grayish brown seams to the cross-veins, deflections of veins, and along 

 Cu, but the wing apex only slightly darkened if at all 33 



31. Coloration of the body yellowish or reddish, the thoracic notum light yellow. [Proc. 



Acad. Nat. Sci. Phila., p. 235. 1859.] (Plate XXXIX, 128.) L. adusta O. S. 



Coloration of the body dark brown to almost black, the thoracic nctum con- 

 colorous 32 



32. I-egs yellow with the brown apices to the segments narrow; costal cell of the wing yellow. 



[Psyche, vol. 18, p. 195-196, pi. 16, figs. 4, 8. 1911.] (Plate XXXIX, 129.) 



L. similis Alex. 



Legs with the femora brown, only a little brightened basally; costal cell of the wings 



brown. [Journ. N. Y. Ent. Soc, vol. 24, p. 123, pi. 8, fig. 7. 1916.] (Plate XXXIX, 



130.) L. terrae-novae Alex. 



