456 



U. S. NATIONAL MUSEUM BULLETIN 216 



PART 3 



Figures 252, 253. — Localities: 252 (left), Mesostenus angustus; 253 (right), M. longicaudis. 



and all of fifth segment fuscous; wings hyaline; abdomen fulvoferrugi- 

 nous, the postpetiole brownish except apically, basal 0.6 ± of second 

 tergite brown, and basal 0.4 ± of third and following tergites brown. 



Female: Head and thorax black and white as in figure 337,f; fla- 

 gellum with an incomplete median white band that covers about 5.5 

 segments; legs fulvous, the front coxa and trochanters mostly whitish 

 and fifth tarsal segments tinged with brown; wings hyaline; abdomen 

 fulvous. 



Specimens (Scf, 189): From District of Columbia (Washington); 

 Illinois (Mahomet) ; Kansas (Lawrence) ; Maryland (Baltimore, Glen 

 Echo, and Takoma Park) ; Missouri (Columbia) ; New Jersey (Haddon 

 Heights and Moorestown) ; North Carolina (Raleigh) ; Ohio (Columbus 

 and North Bass Island) ; Pennsylvania (Gladwyn and Willow Grove) ; 

 Rhode Island (Westerly) ; and Virginia (Great Falls and Rosslyn) . 



Dates of collections are from early to late summer. The earliest 

 and latest records are: June 8 at Lawrence, Kans.; June 15 at Wash- 

 ington, D.C.; September 11 at Takoma Park, Md.; and September 

 12 at Great Falls, Va., and at Columbia, Mo. 



This species occurs in the Carolinian fauna. 



11. Mesostenus longicaudis Cresson 



Figure 337,g 



Mesostenus longicaudis Cresson, 1872, Trans. Amer. Ent. Soc, vol. 4, p. 164; 



9. Type: 9, Bosque Co., Tex. (Washington). 

 Mesostenus macilentus Cresson, 1878, Canadian Ent., vol. 10, p. 210; cf . Lecto- 



type: cf , Louisiana (Philadelphia). 

 Mesostenus gracilipes Cresson, 1878, Proc. Acad. Nat. Sci. Philadelphia, vol. 30, 



p. 365;$, Type: 9 , California (Philadelphia). 

 Coleocentrus texanus Ashmead, 1890, Proc. U.S. Nat. Mus., vol. 12, p. 444; 9 • 



Lectotype: 9, Texas (same specimen as type of Mesostenus longicaudis, 



Washington) . 



