284 BULLETIN 15, UNITED STATES NATIONAL MUSEUM. 



Abdomen a little longer than the head and thorax together, shaped 

 as in F. lupinU-olu. 



In the $ the trochanters, knees, tips of tibiae and tarsi are honey- 

 yellow; abdomen jisin lupin ic<da; tegula' rnfo-piceons; antennae black, 

 the first luniclar joint minute, the second, swollen, curvu'd; club 6- 

 joiuted, the joints, except the last, very little longer than thick; scutel- 

 Inm not tubercular at ti]). 



HA15ITAT. — District of Cohimbia, 



Types in National Mnseum.- 



Described from $ and 9 specimens, reared April 30 and May 1, 1884, 

 from a Cecidomyiid gall, Ccchlomyia scrrnJata O. IS., fonud on alder. 



SACTOGASTER Fr.ister. 

 Hyui. Stud. II, p. 108, 185G. 

 Ejnmeces Westw. (p((rs). 



(Ty])e E. twntraUs Westw.) 



Head transverse, the vertex somewhat acute, the occiput delicately 

 margined; ocelli o, small, triangularly arranged, the lateral distant 

 from the margin of the eye. 



Antenna^ 10-jointed in both sexes, in 9 terininating in a ■4-jointed 

 club; in S Avith a r)-jointed, hairy club, the joints twice as long as thick, 

 the funicle cylindrical, the pedicel shorter than the first two luniclar 

 joints united. 



Thorax subovoid, the mesonotum smooth, a little longer than wide, 

 without furrows, or the furrows only delicately indicated posteriorly; 

 scutellum convex, ending in a thorn, bifoveated at base; metathorax 

 very short with ai median carina, the metapleura with a silvery or 

 hoary pubescen(;e. 



Front wings veinless, pubescent. 



Legs clavate, the basal joint of hind tarsi more than three times as 

 long as the second. 



The females in this genus are readily separated from all others, by 

 the intlated second ventral segment of the abdomen, the males by the 

 position of the lateral ocelli. 



The two species in our fauna may be thus separated: 



TABLE OF SPECIES. 



Head closely, finely, microscopically i>uuctatc, shining. 



Thorax uiicroscdjiicully punitate, parapsidal I'nrrows distinct posteriorly; scn- 

 telluiii, iucta])lenra and base of alxlonien ay ith a silvery pubescence; 

 tail not longer than the first and second segments together. 



S. ANOMALIVENTKIS Ashm. 



Head polished iinpnnctate. 

 Thorax polished, Avithont a trace of the furrows; scutellum striated; metapleura 

 and base of abdomen bare; tail nearly twice as long as the first and 

 second segments together S. Howakdii Ashm. 



