ART. 15». REVISIOX OF SUBFAMILY PLATYOASTERIlSrAE FOUTS. 113 



in the sand, except that its side is a little steeper anteriorly; four or 

 five grooves run out of this pit and extend in a short curve poste- 

 riorly. Black; mandibles, base of scape, anterior tibiae, and all tarsi 

 yellow; scape apically and front legs, except parts mentioned above, 

 brownish; rest of legs and antennae piceous. 



Described from one specimen collected at Cabin John, Mary- 

 land, by the author on May 20, 1917. No ecological data are avail- 

 able. The specimen was probably collected while sweeping in the 

 forest. 



The type is in the author's collection. 



This species is easily separated from all of our described species 

 of Sactogaster. The length of the abdominal "tail" distinguishes 

 it from all except howardii. 



3. SACTOGASTER HOWARDII Ashmead. 



Sactogaster howardii Ashmead, Can. Ent., vol. 20, 1888; Bull. 45, U. S. Nat. 

 Mus., 1893, p. 285. 



Female. — Length 2.4 mm. Head about the same shape as in 

 mucrovata Fouts, about twice as wide as long seen from above, rather 

 full behind the eyes, in front feebly convex; broadly rounded on the 

 sides; seen from in front the head is more or less hexagonal, about 

 as wide as high, the part of the head over the eyes dome-shaped and 

 half as high as the eyes are long, projecting above the eyes about 

 as far as head projects below the eyes; vertex rather acute, rolled 

 up into a ridge which extends laterally a little beyond the lateral 

 ocellus; projection between antennae as in mucronata Fouts; head 

 and thorax, except pleurae, lower part of pronotum and the venter, 

 finely and evenly shagreened as in mucronata; fourth antennal joint 

 about twice as long as wide; notauli nearly complete, faint anteriorly; 

 wings hyaline; tail of abdomen one-tenth longer than the length 

 of the body preceding it; second sternite about twice as long as 

 wide when viewed laterally, extending to apex of second segment, 

 rounded below and apically and flattened above, made to appear 

 like a thick hook by the incision which penetrates to the circular 

 depression at its middle; second tergite rather strongly shagreened 

 on its apical fourth, otherwise smooth and shining, remaining tergites 

 strongly shagreened with indications of diagonal striations; third ter- 

 gite about twice as wide as long, one-third shorter than the fourth 

 which is a little longer than wide; fifth tergite as long as the sixth 

 which is three times as long as wide and pointed apically; sides of 

 the sixth parallel to the apical third of the segment. Black; scape, 

 pedicel, funicle, anterior and middle trochanters, front legs (except 

 coxae and last tarsal joint), middle and posterior tibiae at their basal 

 half, and tarsi (except terminal joints) yellow or yellowish brown; 



