AMERICAN HYMENOPTERA. 57 



inner, au obtuse angle at the reception of the second recurrent nervure. 

 Anfcnnse 3-articulate, simple, ciliate in male. 

 Bodi/ short. 

 Tibise simple. 



1. A. debilis. 



Atomucera debilis, Say, Bost. Jour. I, 1835, 212, 1 . '^ . 

 "Blaek; tibise whitish. Length 0.15 inch. 



% . Body black, polished ; antennae, cilia; longer than the transverse 

 diameter of the antennae ; mouth dull piceous ; wings fuliginous, a 

 little paler at tip ; first and second cubital cellules confluent; tibia-, 

 anterior pair dull pale yellowish." 



Indiana. Not seen. 



Mr. Walsh writes, that he has taken one specimen in Illinois. The 

 antennre about three-fifths as long as body, the third joint of ecjual 

 thickness to the middle, beyond which it tapers a little to the tip ; the 

 first submarginal cross-vein is distinct. lie thinks A. ni/ico/lis to be 

 the 9 of this. 



2. A. cellularis. 



Atoinacera cellularis, Say, Bost. Jour. I, 1S35, 21:'.. 2, J. 



Black; abdomen rufous. Length, less than nno-fuurth of an inch. 

 9 . Body black, polished ; antennte distinctly and rather densely 

 ciliated with hairs, which are a little shorter than the transverse di- 

 ameter of the antennae; nasus, labrum and palpi whitish; wings dusky 

 violaceous; cubital cellules three; the second very small, hardly one- 

 third the length of the first, and but little wider at its tip than at its 

 base; abdomen entirely yellow rufous; feet, coxae, trochanters and 

 base of the tibia) whitish ; anterior pair of tibia; dull whitish. 

 Indiana. 



;;. A. ruficollis. 



Atomarcra rujicollis, Norton, Proc. Ent. Soc. Pliil., 1864, 6, 7, 9 . 

 Black; the prothorax above, niesothorax and scutel rufous; wings sub-viola- 

 ceous. Length 0.17. Br. wingso.40 inch. 



9. Shining black, short and stout; antenna; black, short, thickly 

 ciliate; second joint very short; third hardly clavate, but decreasing 

 gradually in size to tip; the fourth and fifth joints of palpi flattened 

 and enlarged, apical joints of equal length, but slender; basal third of 

 antennae above and beneath ferruginous ; tegulai, anterior angle, nieso- 

 thorax and scutel yellow-red ; legs black, their anterior tibiae dull 

 whitish before, their spurs short and sharp ; wings ample, violaceous, 

 sub-opaque, clearer toward apex, stigma large ; four submarginal cells, 

 second and third each receiving a recurrent nervure; lanceolate cell 

 petiolate; under wings with two middle cells. 



TRANS. AMER. ENT. SOC. ( 8 ) JUNE, ]Sfi7. 



