Vol. IX] VAN DU ZEE— NORTH AMERICAN MEDETERUS 259 



9. Last section of fifth vein only a little longer than the cross-vein. . . 

 cequalis, new species 



-. Last section of fifth vein one and a half times as long as the cross- 

 vein nitidiventris, new species 



10. Femora mostly yellow; mesonotum and aibdomen light green 



longinquus, new species 



-. Femora mostly black ; mesonotum coppery ; abdomen dark green . . 



ceneus, new species 



-. Femora mostly black; mesonotum covered with thick gray pollen. 



falcatus, new species 



11. Bright metallic species 12 



-. Darker species ; generally blackish 16 



12. Length about 2 mm. ; fore tarsi of male with a compressed lobe on 



the third joint lobatus V. D. 



-. Length nearly 3 mm 13 



13. Face and all coxae metallic green; (Eastern states) . .afe^rraM.y Wh. 

 -. Face, front and anterior part of the thoracic dorsum violet ; coxae 



blackish ; (Guatemala) 14 



14. Fore tarsi plain, regularly tapering from base to tip 



planipes, new species 



-. Fore tarsi ornamented 15 



15. Fore tarsi a little widened from base to tip of second joint, third 



joint only a little narrower but suddenly contracted to a slender 

 projection to which the fourth is attached; fourth and fifth 



joints slender ahruptus, new species 



-. Fore tarsi with the second and third joints very much compressed 



and expanded on upper edge; fourth and fifth joints minute 



Aavipes, new species 



16. Bristles above fore coxae black 17 



-. Bristles above fore coxae white or yellowish 28 



17. Second joint of hind tarsi more than twice as long as first 18 



-. Second joint of hind tarsi not more than twice as long as first 19 



18. Legs altogether black nigripes Loew. 



-. Tibiae largely yellowish vittatus, new species 



19. Antennae wholly black 20 



-. Antennae partly yellow 22 



20. Knob of the halteres black halteralis, new species 



-. Knob of the halteres yellow 21 



21. Second joint of hind tarsi fully twice as long as first 



vittatus, new species 



-. Second joint distinctly less than twice as long as first 22 



22. Second joint of hind tarsi one and a half limes as long as first; 



last section of the fifth vein only a little longer than the cross- 

 vein obscuripennis, new species 



-. Second joint of hind tarsi one and a fourth times as long as first ; 

 last section of fifth vein two and a fourth times as long as the 

 cross-vein frontalis, new species 



23. Thorax with distinct gray vittae 24 



-. Thorax without distinct gray vittae 25 



24. With a distinct gray stripe on each side of the acrostichal bristles ; 



male with prominent yellow hairs at tip of hind tibiae 



• viduus Wh. 



-. Thorax with four gray vittae aldrichii Wh. 



25. Mesonotum with thick brown pollen ; length 5 mm 



emarginatus V. D. 



-. Mesonotum with thin grayish pollen; length 3.25 mm. or less 36 



26. Last section of the fifth vein three-fourths as long as the cross- 



vein in the male and a little longer than that vein in the female. 

 oregoncnsis, new species 



