8 U.S. NATIONAL MUSEUM BULLETIN 2 68 



Elevation on the surface of the medial lobe of the clypeus broad and tending 

 to be bidentate (recorded only from the state of San Luis Potosi, Mexico) 



atrata Scullen 



22. Apical clypeal margin with one large process 23 



Apical clypeal margin with more than one process or denticle and these 



relatively small 26 



23. Process on the clypeal margin not acute (one specimen only recorded from 



the type locality which is given as "Mexico") . . cerceriformis Cameron 

 Process on the clypeal margin acute 24 



24. Mandibles with one large obtuse — angulate denticle somewhat divided (Cen- 



tral and northeastern states from Colorado to New England states) 



zonata (Say) 

 Mandibles with one single acute denticle 25 



25. Abdomen largely yellow (Rocky Mountain area, Alberta to western Texas) 



superba superba Cresson 



Basal terga of abdomen ferruginous; apical terga more or less fuscous to 



black (scattered records in the northern Rocky Mountains area from 



Alberta south to western Kansas) superba bicolor Cresson 



26. Two completely separated single, acute, mandibular denticles, one above the 



other 27 



All mandibular denticles on the^dorsal carina 28 



27. Fulvous to ferruginous, vvithout black (south central Texas and northeastern 



Mexico) sinuata Scullen 



Black with yellow markings, very limited fulvous replacing the yellow 

 (known only from the state of Oaxaca, Mexico) . . . menkei, new species 



28. Two closely placed truncate denticles on the clypeal margin with a cluster 



of bristles between them (southwestern states and north central Mexico) 



pimarum Rohwer 



Two widely separated acute, or more than two denticles on the clypeal 



margin 29 



29. Lateral clypeal denticles, approximately at the junction of the medial and 



lateral clypeal lobes, undivided and unidentate 30 



Lateral clypeal denticles either bidentate or divided into two appressed 

 denticles 35 



30. Dorsal body parts black with creamy white or yellow markings, no brown 



or amber markings 31 



Dorsal body parts with brown, red, or amber 34 



31. Markings yellow; enclosure smooth; mandibular denticles undivided (west 



of the Rocky Mountains in the United States) . . . similis Cresson 



Markings creamy white; enclosure ridged; mandibular denticle bicuspi- 



date 32 



32. With a small, single, mesal denticle just above the median teeth on margin 



of medial clypeal lobe (state of San Luis Potosi, Mexico and adjoining 



areas) baccharidis, new species 



With a pair of medial denticles a short distance above apical margin of the 

 medial clypeal lobe 33 



33. Venter fuscous to black (mostly known from central plateau of Mexico, 



rarely from Texas and New Mexico) . . . morula morula, new species 

 Venter ferruginous to fulvous (south central New Mexico and western Texas) 



morula albarenae, new subspecies 



