WALSH DESCRIPTIONS OF N. AM. HYMENOPTERA. 1 59 



rupted on its middle ^, and in 3 and 4 notxjuite attaining the lateral mar- 

 gin. Ovipositor § as long as the body, piceous; sheaths black, tapered, 

 slightly expanded at the extreme tip. Venter dull luteous except at tip, 

 much inflated, and longitudinally carinate. Four front legs pale rufous; 

 middle legs with the knees white, the upper face of the femora and the sub- 

 basal suture of the tibiae obfuscated, and the last tarsal joint black. Hind 

 legs black, with the trochanters, the inner surface of the middle of the tibiae, 

 and tarsal joints 1-4, cloudy rufous; and the basal i of the tibiie white. 

 H^i«<75 subhyaline ; veins black; stigma black, its basal \ white. Radial 

 area 3i times as long as wide. Length $ .43 inch. Front wing $ .30 inch. 

 Ovip. .26 inch. 



One $ ; S unknown to me, but in all probability will have a 

 white face. By far the smallest N. A. species yet described, and 

 distinct at once by its semifasciate abdomen. 



Genus ECHTHRUS, Gravenhorst. 

 This genus may be recognized by its subpetiolated abdomen 

 and nearly cubical head, and by its pentagonal areolet. The group 

 in which the areolet is obsolete would seem to belong to a distinct 

 subgenus. In mv species the clypeal suture is obsolete, but the 

 two foveas that normally lie in that suture are present, and indi- 

 cate that the clypeus is typically as short as it is in Odontomerus 

 and Xylonomus, thus exposing a large portion of the labrum in all 

 these genera. I do not find this character referred to anywhere 

 by authors, but it is obvious in E. rebtctator (Europe). The 

 mandibles are toothed as in Odontomerus. The bullae are large 

 and generally 4 in number, A, B, CD, and E ; A indistinct, rarely 

 obsolete ; B sometimes occupying the whole exterior side of the 

 areolet; CD often with a dark dot between them and together 

 occupying the middle \ of the 2d recurrent vein, which is usually 

 perfectly straight ; and E pretty close to the crook of the i st re- 

 current vein. In E. {^Cryptus) ornatipennis, Cresson, which is an 

 aberrant species in other respects, the ist recurrent vein is nearly 

 straight, E is close to the areolet, and CD adjoins the areolet. 



Echthrus annnliCOrniS, n. sp.—$.— Black. Head opaque, very mi- 

 nutely and densely rugoso-punctate, subopaque on the vertex. Mandi- 

 bles (except their teeth and their lower edge) and labrum rufous. Palpi 

 whitish. Antennae brown-black, | as long as the body, obviously clavate, 

 the terminal \ of the flagellum being nearly twice as thick as the extreme 

 base ; joint i of the flagellum slender and 4 times as long as wide, 2 shorter 

 by J, and the following joints very slowly shorter; joints 7-9 of the flagellum 

 whitish. Thorax opaque, very minutely and densely rugoso-punctate, sub- 

 glabrous and polished on the pleura. Parapsidal grooves subobsolete. Meta- 



