8 PROCEEDINGS OP THE N^ATIONAL MUSEUM vol.67 



longer than femur, basitarsus barely as long as next three joints; 

 abdomen narrower, second tergite much longer than broad at apex; 

 abdomen apically immaculate; apical joints of all trochanters 

 testaceous. 



Type-locality. — Ohio. 



Type.—Csit. No. 27684, U.S.N.M. 



One of each sex received from Prof. C. H. Kennedy of Ohio State 



University. 



Genus SYZEUCTUS Foerster 



Foerster, Ashmead, and Schmiedeknecht all employ as one of the 

 key characters ascribed to this genus the lack of a carina separating 

 metapleurum and propodeum. As a matter of fact, the genotype, 

 maculatorius (Fabricius), frequently has a more or less developed 

 carina, while the two species described below have it well developed. 

 The only real difference between the present genus and its nearest 

 relative, Diceratops Foerster, lies in the frontal horns of the latter. 



SYZEUCTUS SIGMOID ALIS, new species 



Especially remarkable for the peculiar nervellus. 



Female. — Length, 9 mm.; antennae, 7.5 mm.; ovipositor, 6.5 mm. 



Head transversely oval, temples convexly sloping; postvertex 

 (that portion of the head lying between the ocelli and the occipital 

 carina) medially impressed, polished with a few scattered punctures; 

 temples with more numerous punctures, running into fine shagreen- 

 ing on cheeks; vertex and frons more densely punctate, the latter 

 medially slightly concave; aface similarly punctate, strongly convex, 

 with a rather deep impression on each side just below level of 

 antennae; clypeus separated from face by a broad deep groove; 

 polished with few punctures; malar space nearly as long as basal 

 width of mandible. Thorax and prododeum with coarse and dense 

 but distinct punctures, finer and closer on prescutum, coarsest on 

 propodeum; apical and pleural carinae complete; nervellus a sig- 

 moid curve, more strongly curved below where it turns backward 

 and is apparently continuous with the obsolete discoidella; hind 

 tibia about one and one-half times as long as femur, basitarsus as 

 long as three following joints. Abdomen minutely and faintly 

 shagreened and sparsely and finely punctate, broadly polished; 

 first tergite two-thirds as broad at apex as long, sides straight, 

 spiracles at basal third; tergites 2-4 as long as broad at base, others 

 successively rapidly shorter. 



Black with abdomen partly red; upper anterior and posterior 

 orbits, broad on frons and narrowly confluent on apex, clypeus at 

 apex, and spot on base of mandible yellow; antennae black basally 

 and above, brown beneath nearly to base of flagellum; palpi brownish 

 testaceous. Thorax immaculate; tegulae piceous; wings hyaline. 



