AMERICAN HYMENOPTERA. 195 



T(ihular Si/nojisis to assist in finding the sjjecies. 



1. Head above the antennpe black. 



A. Body and legs black 1, concolor. 



£. Thorax black. » 



a. Abdomen black. 



1. Tegulse and trochanters black 2, Labradoris. 



2. ToguliB and trochanters jjale 3, malacus. 



b. Venter more or less pale. 



1. TegulfB and trochanters black 4, extensicornis- 



6, marylandicus. 

 (), fallax. 



2. TegTilaj and Irocbaiiters pale 7, suratus. 



s, Winnipeg. 

 30, ventricosus. 

 9, monela. 



10, subalbatus. 



11, corniger. 



12, luteolus. 



c. Abdomen banded with rufous 24, erythrogaster. 



C. Thorax black, pectus pale 13, Saskatchewan. 



J). Thorax pale, a black spot on i^ectus 44, bivittatus. 



2. Head above antennae more or less pale. 

 JS. Thorax black. 



«. Venter more or less pale. 



Trochanters black 14, violaceipennis. 



15, nigritus. 



Trochanters pale 10, ventralis- 



17, longicornis. 



18, proximatus. 

 11, corniger 9 • 



19, pallicornis. 



20, obscurus. 



21, S. pisum. 

 b. Abdomen banded with red or yellow 22, brunneus. 



23, rufofasciatus. 

 25, luteotergum. 

 36, fur. 



27, Hudsonicus. 

 I". Thorax black, pleura pale 2S, sumptus. 



29, pleuricus. 



30, ventricosus, 9- 



31, lateralis. 



32, desmodioides. 



33, fulvipes. 

 G. Thorax mostly pale 34, crassus. 



a. Pectus black, a pale spot in middle 35, placentas. 



6. Pectus pale. 



Thorax trilineate with black, pleura with two spots. ..30, inquilinus. 



jileura with one spot 37, longulicornis. 



scutel black 38, trilineatus. 



