ART. IG WASPS OF THE SUBFAMILY BEACONINAE MUESEBECK 1 1 



tellum not margined at apex; mesopleural furrow finely foveolate; 

 prepectal carina wanting; propodeum rugulose, with two slightly di- 

 verging median carinae; wings as in Bassus; first cubital and first 

 discoidal cells confluent; second cubital cell triangular, sessile; spurs 

 of hind tibia less than half the length of basitarsus; several short 

 stout spines at apex of posterior tibiae above the outer terminal spur; 

 tarsal claws simple, or with an indistinct basal tooth; abdomen slen- 

 der, rather broadly sessile, the basal tergites more or less sculp- 

 tured; hypopygium moderate, not surpassing apex of last dorsal seg- 

 ment; ovipositor long. 



This genus is represented by a single known species. 



AENIGMOSTOMUS LONGIPALPUS (Cresson) 



Microdus? longipalpus Cresson, Proc. Ent. Soc. Phila., vol. 4, 1865, p. 299. 

 Aenigmostomus longipalpus Ashmead, Proc. U. S. Nat. Mus., vol. 23, 1900, p. 

 128. 



Type. — No. 2745, Academy of Natural Sciences, Philadelphia, 

 Pennsylvania. 



The following characters, combined with the above generic descrip- 

 tion, will identify this species: Temples rather broad, but sloping off 

 gradually, not bulging; cheeks strongly receding; antennae usually 

 24 to 26 segmented, the flagellum slender, not tapering at all to the 

 apex; ocell-ocular line distinctly less than twice the diameter of an 

 ocellus and scarcely as long as the postocellar line; no tubercles 

 between antennae; outer margins of antennal foramina very close to 

 the eyes; mesoscutum and scutellum polished, the latter flat; meso- 

 sternum fully as long as broad ; propodeum finely rugulose, with two 

 prominent median carinae which diverge slightly behind ; the dorsal 

 face of propodeum long and only very slightly declivous; propodeal 

 spiracle very small, nearly circular; radius arising from about the 

 middle of stigma ; areolet triangular, sessile ; first abscissa of mediella 

 slightly longer than the second; nervellus angled and emitting the 

 discoidella from this angle; posterior tibiae distinctly shorter than 

 their tarsi ; the terminal spurs of hind tibia of equal length and only 

 about one-third as long as the posterior basitarsus ; last segment of 

 hind tarsi shorter than the third: first abdominal tcrgite scarcely 

 longer than broad, impressed at base, with two widely separated 

 dorsal longitudinal keels, and finely longitudinally rugulose; second 

 tergite very finely sculptured and with a more or less distinct trans- 

 verse impression just behind the middle; remainder of abdomen 

 pohshed; ovipositor sheaths a little longer than the entire body. 

 Head and thorax black ; wings uniformly infuscated ; legs, including 

 all coxae, testaceous; all tarsi more or less dusky; abdomen yellow- 

 ferruginous, the first tergite except at apex, and sometimes more or 

 less of the apical segments, blackish. 



