284 BULLETIN 15, UNITED STATES NATIONAL MUSEUM. 



Abdomen a little lonj>er than the liead and thorax together, shaped 

 as in P. lupinkola. 



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

 yellow; abdomen nsiulupitiicoht; teguhe rnfo picivms ; antenna^ black, 

 the first fnnidar joint niinute, the second, swollen, cnrvcd; clnb 6- 

 jointed, tlie. joints, except the last, very little longer than thick; st^utel- 

 Inni not tiibcrcnhir at tip. 



IlAiUTAT. — District of Colnmbia. 



Types in Xatiimal IMnscnni. 



Described from 3 and 9 specimens, reared April 30 and May 1, 1884, 

 from a C'ecidomyiid gall, Cccitlomyiu nerrulata O. S., found on alder. 



SACTOQASTER Foister. 

 Ilym. StiuK ii, p. 108, 1856. 

 Epimecea Westw. (pars). 



(Type E. ventralis Westw.) 



Head transverse, the vertex somewhat acute, .the occiput delicately 

 margined; ocelli .">, small, triangularly arranged, the lateral distant 

 from the margin of the eye. 



Antenns^ 10-Jointed in both sexes, in 9 teriuiiiating in a l-jointed 

 club; in $ with a a jointed, hairy club, the joints twice as long as thick, 

 the funicle cylindrical, the i)edicel shorter than the flrst two funidar 

 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; metatliorax 

 very short with a median carina, the nietapleura with a silvery or 

 hoary pubescence. 



Front wings veinless, pubescent. 



Legs <;lavate, the basal joint of hind tarsi more than three times as 

 long as the sec<md. 



The females in this genus are rea^lily separated from all others, by 

 the inflated 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 punctate, shining. 



Thorax microscopically pnnctat*', parapsidal furrows distinct posteriorly; scn- 

 tellum, iiicta]»le»irir !ind base of abdomen with a silvery j)ubc8cence; 

 tail not longer than the first and second segments together. 



S. ANOMALIVENTRIS Ashm. 



Head polished impnnctate. 



Thorax polished, without a trace of the furrows ; scntellnm striated; metapleura 

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

 second segments together S. HowaRDII Ashm. 



