374 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. 



antennae; antennae short, third joint never elongate, 

 rarely almost twice as long as wide (Europe) ; abdomen 

 often with yellow markings; hind femora slightly to 

 much thickened, if much thickened the ventro-apical 

 region bearing two rows of very short spine-like hairs; 

 females more often than the males with yellow mark- 

 ings. In our species the development of the hind 

 femora is equal in the two sexes. 



Key to Species 



1. Abdomen with yellow spots 2 

 Abdomen wholly black 5 



2. Abdomen with four yellow spots quadrimacidata 

 Abdomen with only two yellow spots 3 



3. Hind femora considerably incrassate and bearing spinules near the end 4 

 Hind femora only slightly incrassate; spinules wanting; wings 



never clouded nigripilosa 



4. The spinelike hairs not borne on a triangular projection; tarsi 



wholly yellow festiva 



Spinelike hairs borne on a triangular projection; apical one or two 



tarsal joints blackish femoralis 



5. Hind femora with spinose area near the end, often greatly enlarged 6 

 Hind femora without rows of spinules, never much enlarged 11 



6. Legs and tarsi entirely black; hind femora considerably enlarged; 



face without shining median stripe oregona 



Legs or tarsi in part yellow; hind femora variously enlarged 7 



7. Hind femora very much enlarged; wings hyaline or tinged with 



luteous between veins 8 



Hind femora moderately enlarged ; wings darkened or clouded 9 



8. Hind femora with greatest enlargement beyond the middle; an- 



tenna? entirely blackish macrofemoralis 



Hind femora with greatest enlargement at the middle; second an- 



tennal joint reddish grandij em oralis 



9. Ventral apex of fourth segment narrowly emarginate at its middle; 



face partly black pilose; (about 9 mm., eastern) severnensis 



Ventral apex not emarginate 10 



10. Second segment with faint indications of yellow spots; face chiefly 



whitish pilose femoralis 



Second segment entirely black; wings not clouded, evenly diluted 



with pale brownish; face chiefly black pilose tricolor 



11. Squama? dark, fringed with black hairs distincta 

 Squamae fringed with whitish hairs 12 



12. Abdomen wholly with black or brownish black pile nigripilosa 

 Abdomen in large part whitish pilose 13 



13. Face wholly white pilose or with shining median stripe, (larger, 7.5 



to 9 mm.) 14 



Face black pilose near the mouth only (6 to 8 mm.) puella 



Face entirely black pilose (about 6 mm.) vanduzeei 



14. Pile short; face short, third antennal joint rather long; front very 



broad; thorax brassy black latijrons 



Pile long ; thorax steely black; face rather long, with slender median 



shining stripe davidsrmi 



