AMERICAN HYMENOPTERA. 391 



The % has the clypeus pyriform, rounded above; the apex roundly incised ; 

 the scape of antennas is yellow below; there is a yellow line on the base of the 

 mandibles, one on the lower edge of the eye incision ; there are two short lines, 

 the one below the other above the antenna? ; the antennal hook is stout, black ; 

 the 1st abdominal segment is punctured, somewhat strongly, not smooth as in 

 the 9 ; the 2nd is punctured throughout ; the apex of the postscutellum is punc- 

 tured, and that of the metanotum rougher. 



The flagelluni of the antennae is rufous below ; the bands on the 

 5th and 6th abdominal segments are wider than those on the mid- 

 dle ones. Comes, in Saussure's system, Syn. of Amer. Wasps, 238, 

 near to 0. brachyg aster Sauss. It is also related to 0. halmus, here 

 described, but that may be readily known from it by the metanotum 

 having a large mark on the sides, not a narrow line, and the line 

 on the 1st abdominal segment is dilated backwards into a large 

 spot. The lateral angles of the metanotum may be black, and the 

 clypeal teeth rufous. 



Ancistrocenis argelus sp. nov. 



Black ; the clypeus, a line on the centre of the basal half of the mandibles, a 

 line above the antennae, its lower half narrowed, a line on the lower edge of the 

 eye incision, a short line behind the top of the eyes, a line on the apex of prono- 

 tum, one united to it on the inner side of the pronotum, postscutellum and the 

 apices of all the abdominal segments yellow, the yellow on the thorax and abdo- 

 men tinged with rufous; the sides of the apical slope of the metanotum broadly 

 dull yellow, tinged with rufous. Antennal scape yellow, the flagelluni rufous- 

 brown beneath. Tibia? yellow in front, the femora tinged with brown, apex of 

 tarsi rufotestaceous. Wings hyaline, tinged with fulvous in front ; the costa and 

 stigma fulvotestaceous, the nervures darker colored. % . Length to end of 2nd 

 segment 7 mm. 



Clypeus longer than wide, sparsely, weakly punctured, the apex with a dis- 

 tinct rounded incision. Front and vertex closely, rugosely punctured ; apex of 

 mandibles rufous. Prothorax and mesothorax closely and strongly punctured 

 above, more sparsely and weakly on the sides, a wide irregular furrow on the 

 centre of the mesopleura?. Pase of thorax transverse, the outer angles acute; 

 the sides of the metapleura? bluntly rounded, rough, the upper sides of the meta- 

 notum irregularly reticulated, thickly covered with fulvous pubescence. Apex 

 of metapleura? with scattered punctures, the base covered with fulvous pile. 

 First ahdominal segment elongated cup-shaped ; there are two indistinct sutures 

 only indicated on the sides, the apical being more distinct than the basal ; the 

 segment is strongly punctured and covered with fulvous puhescence; the 2nd 

 segment is clearly narrowed at the base ; it is punctured ; its apex and the other 

 segments are more coarsely punctured ; the apical edge of the 2nd is weakly 

 raised. Antennal hook stout, black, reaching to shortly beyond the base of the 

 penultimate joint. 



Belongs to Saussure's Section 3, Syn. of Amer. Wasps, 206. 



TRANS. AM. ENT. SOC. XXXI. OCTOBER, 1905. 



