Art. III.] Cockerell, New Mexico Bees. 55 
22. Face below level of antennae all yellow or white, except 
clypeal dots in some. (Males ) . . 23 
Face below level of antennae not all pale, . 43 
23. Face below antennae white, ... 24 
Face below antennae yellow, . . . ,26 
24. Abdomen oval, reddish brown, suffused with darker ; cly- 
peus tinged with yellow ; front nude and very shiny. 
(Las Cruces, Aug.) . . crassiceps, Ckll. var. 
Abdomen yellowish-white, banded; face below antennae 
pellucid white; first four legs ail dull white except a 
dark streak on middle tibiae. (Mesilla Valley, at fls. of 
Bigelovia.) .... pellucida^ Ckll. 
Last three segments of abdomen rufous, the others banded. 
(Albuquerque, La Tenaja, at fls. of Croton.) crotonis, Ckll. 
Abdomen dark brown with white markings, . 25 
25. Abdomen with about 6 white marks, or fewer yellowish 
spots. (Mesilla Valley, at fls. of Pectis.) pectidis^ Ckll. 
Abdomen with two more or less developed white bands, 
. . . . cladothrids, Ckll. 
26. Anterior and middle femora marked with black, . 27 
Anterior femora all yellow, the four anterior tibiae not all 
yellow, ...... 33 
First four legs all yellow, or at least not marked with 
black or brown, ..... 34 
27. Nervures pallid, ..... 28 
Nervures dark, ..... 29 
28. Stigma margined with brown ; venter of abdomen immac- 
culate in middle, . . . sphcrralcece., Ckll. 
Stigma pale orange, not margined with brown ; venter 
with a series of large black patches down the middle. 
(Mesilla Valley, at fls. of Verbesina.) perpulchra^ Ckll. 
29. Face nearly bare, bright yellow below antenna, . 30 
Face and disc of mesothorax hairy, . . 32 
30. Very small, abdomen yellow with pale suffused brown 
bands. (Mesilla Valley, at fls. of Pectis.) biparticeps^ Ckll. 
Abdomen dark with clean-cut interrupted yellow bands, 31 
31. Small, 45^ mm. long. (Mesilla Valley, May, at fls. of 
Erigeron.) .... erigeronis, Ckll. 
Larger. (Embudo, Sept., at fls. of Bigelovia.) affinis., Cress. 
32. Head broader than long ; distal band on 2nd abdominal 
segment broadly continued to lateral margin, 
sphceralcece race alticola, Ckll^ 
Head round : distal band of 2nd abdominal segment fail- 
ing some distance before lateral margin. (Mesilla Val- 
ley, May.) .... hirsuta, Ckll. 
33. Face not all yellow up to middle ocellus. (Mesilla Valley, 
at fls. of Bigelovia.) . . . maculipes, Ckll. 
