210 U. S. NATIONAL MUSEUM BULLETIN 216 



keepsie) ; North Carolina (Crab tree Meadows in Yancey Co. at 3,600 

 ft., Craggy Gardens in Buncombe Co. at 5,300 ft., Hamrick, Linville 

 Falls, Mount Mitchell at 6,400 ft., Mount Pisgah at 5,000 to 5,749 ft., 

 and Wake Co.) ; Ohio (Bridgeport) ; Ontario (Ottawa) ; Pennsylvania 

 (Allegheny Co., Powermill Nature Reserve in Westmoreland Co., 

 and Spring Brook) ; South Carolina (Columbia and Greenville) ; 

 Tennessee (Sevierville) ; Texas (San Antonio) ; Virginia (Barcroft, 

 Chain Bridge, East Falls Church, Falls Church, and Rosslyn) ; West 

 Virginia (Bolivar); and Wisconsin (La Crosse Co.). 



Adults occur from rather early spring to rather late fall. Early 

 and late seasonal catches are: March 23 near Archer, Fla. ; April 4 at 

 San Antonio, Tex. ; April 23 in Wake Co., N. C. ; April 25 at Columbia, 

 S. C; May 9 at Takoma Park, Md.; October 3 at Greenville, S. C; 

 October 1 1 at Falls Church, Va. ; and October 28 at Takoma Park, Md. 



We find the subspecies flying about shrubs or low trees in open 

 deciduous woods or overgrown fields, in relatively dry habitats. It 

 is one of the species of Exochus with a strong odor. 



This subspecies occurs in the Alleghenian, Carolinian, and Austro- 

 riparian faunas. Adults fly through most of the growing season and 

 are moderately common in open dry woods or overgrown fields. 



IX. SULCATUS GROUP 



Front wing 3.8 to 4.0 mm. long; head tapered to narrow mouth, the 

 temples rather narrow; face moderately convex, its interantennal 

 process short, its point with a 120-degree angle; frons approximately 

 flat but with a conspicuous median longitudinal swelling below the 

 front ocellus; occipital carina absent; clypeal margin convex, the 

 curvature somewhat flattened medially; head pale stramineous, the 

 occiput and area surrounding the ocelli blackish; notaulus moderately 

 long and distinct; sternaulus exceptionally distinct, rather sharp and 

 extending about 0.3 the length of the mesosternum; metapleurum 

 without discal hairs; costula, median longitudinal carinae, and apical 

 transverse carina of propodeum all strong; second lateral area of 

 propodeum with a few hairs apically, or bare; nervulus beyond basal 

 vein by 0.5 its length; front spur of middle tarsus about 0.60 as long 

 as hind spur; second segment of middle tarsus about 2.05 as long as 

 wide in male, about 1.7 as long as wide in female; hind tibia pale 

 stramineous, its base infuscate and its front side with a weakly in- 

 fuscate stripe; first tergite about 2.4 as long as its width at basal 

 corners; second abdominal tergite about 0.68 as long as wide, its 

 punctures exceptionally fine and weak, their interspaces about 4 to 7 

 times their diameter; epipleurum of third tergite moderately wide, 

 subtruncate posteriorly, its mesal and basal margin evenly convex. 



