OF WASHINGTON, VOLUME XIV, 1912. 149 



7 with one on dorsum near apex. Mouth cone slender, nearly attaining 

 mesosternum; labium broadly rounded at tip, slightly surpassed by labrum. 



Prothorax somewhat more than half as long as head and (inclusive of 

 coxse) about 2.4 times as wide as long; pronotum non-sculptured, anterior 

 and posterior margins concentric; all usual bristles present, subequal and 

 dilated at tip, about as long as postoculars. Pterothorax usually slightly 

 wider than prothorax, sides straight and converging posteriorly. Wings 

 more or less clouded with brown, distinctly broader in basal than in apical 

 half, slightly narrowed at middle, not closely fringed (the posterior margin 

 with only about 52 hairs), subapical fringe double for about nine hairs. 

 Legs rather stout; fore tarsus with a short, stout, acute tooth. 



Abdomen little, if any, broader than pterothorax, broadest toward base, 

 thence rounded gradually to base of tube. Tube about half as long as 

 head, about twice as long as basal width, and slightly less than twice as 

 wide at base as at apex, sides straight. Lateral bristles long, three-fifths 

 the length of tube, knobbed, yellowish, two pointed pairs at apex of seg- 

 ment 9 longer; terminal bristles about 1.5 times as long as tube, brown. 



Measurements of holotype: Length 1.38 mm.; head, length 0.228mm., 

 width 0.197 mm.; prothorax, length 0.124 mm.., width (inclusive of coxae) 

 0.292 mm.; mesothorax, width at anterior margin 0.292 mm.; metathorax, 

 width at posterior margin 0.246 mm.; abdomen, width 0.300 mm.; tube, 

 length 0.120 mm., width at base 0.056 mm., at apex 0.036 mm. Antennal 

 segments: 1, 24 M ; 2, 48 M ; 3, 54 M ; 4, 57 M ; 5, 51 //; 6, 47 /*; 7, 42 M ; 8, 29 M ; 

 total length of antenna, 0.35 rnm., width at segment 4, 0.033 mm. 



Male. Length about 1.3 mm. Head very slightly, if any, longer than 

 in female. Fore femora and tibiae swollen ; tarsal tooth stronger. Pro thora- 

 cic and postocular bristles longer than in female, the pair at the anterior 

 angles unusually long, much longer than the eyes. 



Described from 14 females and 1 male, as follows : Illinois : 

 Carbondale, October 12 and 15, 1908, L. M. Smith, on br;uu i s 

 of sycamore and post oak (Quercus stellata Wang.); Anna, 

 October 26, 1908, L. M. S., on branch of sycamore; Monti- 

 cello, August 1, 1908, C. A. Hart, on branch of willow birch; 

 Pulaski, October 27 and 28, 1908, L. M. S., on branch of white 

 oak (Quercus alba L.) and swamp oak (Q. palustris Muench.). 

 Missouri: Wittenberg, July 12, 1909, C. A. H., on branch of 

 walnut. Maryland : Plummer's Island (in the Potomac River 

 near Washington, D. C.), May 19, 1912, W. L. McAtee and 

 J. D. H., on branch of Quercus sp. District of Col um bia: 

 Washington, July 28, 1912, J. D. H., on branch of yellow 

 locust (Robinia pseudacacia L.). 



Type locality : Carbondale, Illinois. 



This species is one of the commonest and most widely dis- 

 tributed ones of 1 he genus. Mr. A. C. Morgan has shown me 

 a specimen from Florida, in the collection of the Bureau of 



