68 AMERICAN HYMENOPTERA. 



A large patch of black hair between the wings, but anterior part of mesothorax 

 and soutellnm, with no admixture of black; hind legs covered with 

 black hair ';Pennsylvania) boinboides Kirby. 



The black hair interspersed among the rest, not forming a definite patch 1. 



1. Abdomen with dense, entire, well-defined hair-bands. 2. 



Abdomen with thin, interrupted hair-bands, or none (the species of this group 



are superficially very much alike) 3. 



2. Hair-bands of abdomen fulvous (Catalina I) catHliiiie Ckll. 



Hair-bands of abdomen pale ochreous urbana Cress. 



' Hair-bands of abdomen white; larger than urbana, with the third antennal 

 joint much longer washingtoni Ckll. 



3. Males 4. 



Females fi 



4. Middle tarsi with very long pure white hair, some black on first joint; face- 



marks deep chrome yellow pacifica Cress. 



Middle tarsi with red hair ; last joint with a black fringe 5. 



5. Scutellum without any intermixture of black hair; abdomen without light 



bands ; upper part of clypeus black, except a small median mark. 



ursina Cress. 

 Scutellum with black hair intermixed ; abdomen with at least traces of light 

 bands; clypeus yellow, with two large black marks on upper part. 



simillima Cress, (syn. euops Ckll.). 



6. Very large and robust ; abdomen not at all seneous or bluish ; hair of scutel- 



lum white with no admixture of black porterse Ckll. 



Abdomen distinctly seneous or bluish ; scutellum with some black hair; third 

 abdominal segment with some or much black hair; hair on outer side 

 of hind tibiae shining white 7. 



7. Larger, size of porterse ; second abdominal segment with some black hairs. 



ignava Cress. 



Smaller; second abdominal segment with hair all white, strongly contrasting 



with third 8. 



8. Third abdominal segment with the hair all black, except the thin (broadly 



interrupted) apical band edwardsii Cress 



Third abdominal segment with the hair mixed black and white throughout. 



gohrmaiiie Ckll. 



Group E. (Series 2). 



Large species ; hair of thorax above without black. 



(The division of group E into series 1 and 2 is purely artificial for con- 

 venience of identification. In the case of ^4. (/o/inrtana;, the sexes fall in 

 different sections.) 



Males. 1. 



Females 6. 



1. Large; apical part of abdomen thickly covered with yellowish or fulvous hair, 



like the anterior part; basal joint of hind tarsi spined about the mid- 

 dle occideii talis Cress. 



More than apical half of abdomen appearing black, being bare or with mainly 

 black hair 2. 



2. Basal joint of hind tarsi spined or toothed in front 3. 



