1903.] NATURAL SCIENCES OF PHILADELPHIA. 609 



4. Basal half of abdomen not red, 5. 



First abdominal segment red; clypeus red, lateral face-marks 



white snowii, Cr. (D.), 



Abdomen red with white bands, ridingsii, Cr.(D.). 



5. Mesothorax with obscure reddish stripes; size large, abdomen very 



broad, erigeronis, Rob. 



Mesothorax without any red; size smaller, abdomen not so 

 broad, 6. 



6. Legs largely yellow; clypeus yellow, .... /ormw/a, Viereck. 

 Legs red, 7. 



7. Mesothorax with the punctures well separated, 8. 



Mesothorax with the punctures extremely dense, .... 9. 



S. Markings creamy-white, vierecki, Ckll. 



Markings lemon-yellow, putnami, Cr. (D.). 



9. Clypeus red, ... inodesta var. vegana, Ckll. 



Clypeus black, 10. 



10. Metathorax with yellow spots, modesta, Cr. 



Metathorax without yellow spots, 11. 



11. Lateral face-marks white, heiligbrodtii, Cr. (D.). 



Lateral face-marks yellow, 12. 



12. Punctures of mesothorax smaller, texana, Cr. 



Punctures of mesothorax larger, 13. 



13. Flagellum black beneath, . . . modesta var. rivertonensis , Ckll. 

 Flagellum red beneath, neomexicana, Ckll. 



Males. 



Apex of abdomen entire; supraclypeal mark surrounded by black, 



lippice, Ckll. 

 Apex of abdomen notched, though sometimes feebly, .... 1. 



1. Flagellum with a light median area, on each side of which is 



black ' 2. 



Flagellum ordinary, not so colored, 6. 



2. Tegulse pale yellow or whitish, 3. 



Tegulse deep ferruginous, 5. 



3. No supraclyjDeal mark, scitiformis, Ckll. 



Supraclypeal mark present, 4. 



4. First abdominal segment largely red, witiiout light markings, 



sophiarum. Ckll. 

 First abdominal segment black, with a narrowly interrupted cream- 

 colored band, scita, Cr. 



5. Ground color of abdomen nearly all red, 



americana var. dacotana, Ckll. 

 Grovmd color of abdomen red basally, otlierwise black, 



americana, Kirby. 



6. Metathorax with yellow spots modesta, Cr. 



. Metathorax without yellow spots, 7. 



7. Size larger; ajDex of abdomen very deeply emarginate; no supra- 



clypeal mark, crassnJaXkW. 



Size smaller; apex of abtlomen not so deeply emarginate, . 8. 

 39 



