INSECUTOR INSCITI^ MENSTRUUS 23 



Blackish, cinereous pollinose. Antennae, frontalia, palpi, and 

 legs black. First two abdominal segments subshining brown- 

 ish-black ; the second rather broadly pollinose on base except 

 on median line, the pollen area of each side distended pos- 

 teriorly next median line. All other parts thickly pollinose, 

 the bristle origins of last two abdominal segments marked with 

 black dots. Wings clear. Tegulas watery-whitsh. Thoracic 

 vittae practically obsolete. 



Holotype, No. 19566, U. S. Nat. Mus. 



Named in honor of Mrs. A. T. Slosson. 



Family DEXIID^ 



Spathidexia Townsend. 



Genotype, Spathidexia clemonsi Townsend, 1912, Journ. 

 N. Y. Ent. Soc, XX, 110. 



Differs from Thelairodes as follows: Both sexes with two 

 proclinate fronto-orbitals. Hind claws of male about as long 

 as others, all thickly pubescent. Costal spine vestigial, or 

 slightly developed. Arista short-hairy above and below. Fe- 

 mora not modified, tibiae not hairy. Male front at vertex about 

 *.wo-thirds of eye. Palpi of male short, small, little swollen 

 apically. Third antennal joint of male bulged on upper 

 border. 



Female claws short. Female front and face about same 

 width, as wide as one eye or slightly wider. Palpi of female 

 elongate, much enlarged apically. Long heavily-chitinized 

 blade-like larvipositor present, projecting posteriorly and not 

 downward. This larvipositor can not be used for piercing 

 skin of host, since there are no heavy muscles in connection 

 with it. 



Spathidexia clemonsi Townsend. 



Length of body, 6.5 to 7.5 mm. ; of female wing, 5.5 mm. ; 

 of male wing, 6 mm. Three females, Lexington, Kentucky; 

 Melrose Highlands, Massachusetts (demons) ; Rock Creek 

 Park, District of Columbia, May 23, 1915 (Townsend) ; one 

 male, Riverton, New Jersey, May 30 (C. W. Johnson). 



