BEES OF BOULDER COUNTY, COLORADO 247 



First recurrent nerwire meeting, or almost meeting, first transverse-cubital; nervures 



dark 2. 



2. Flagellum ferruginous beneath cressoniellus Ckll. 



Flagellum dark (Ward, fls. Calochortus) .... cressoniellus calochorti Ckll. 

 P. cressoniellus (clypeatus Cresson) was originally based on a male. As shown 

 above, and in more detail in Ann. Mag. Nat. Hist., Feb. 1906, there are two forms 

 of the female. The one first made known was assumed to be true cressoniellus, 

 but it is not certain which really belongs to the described male, nor whether the 

 males corresponding to the two females can be distinguished. 



SPINOLIELLA Ashmead 

 Clypeus all light except dots and edge, face densely bearded with white hair. 



australior Ckll.i* 



Clypeus only partly light; females i. 



I. Band on third abdominal segment always interrupted; fifth segment black, with 



neither lands nor spots (Fort Collins) australior Ckll.* 



Band on third segment usually entire; fifth segment largely pale (Florissant) 



scitula (Cresson)* 

 5. australior usually visits Peritoma serrulatum. 



PERDITA Smith 

 Pale yellow (Denver, fls. Nuttallia, July, S. N. Dunning) . . wootonae Ckll.* 

 At least head and thorax mainly dark i. 



1. Abdomen light yellow, with dark bands (Ft. Collins, fls. Peritoma) 



zebrata Cresson* 



Abdomen dark brown or black, with or without hght marks . . . .2. 



2. No light supraclypeal mark 3. 



The supraclypeal region yellow (Boulder) affinis Cresson ^ 



3. Light markings of abdomen large, oblique, some reaching lateral margin 



aflSnis Cresson? 

 Light markings of abdomen smaller, transverse, not reaching lateral margin, in 

 female, absent in male; female with clypeus and lateral face-marks white; male 

 with face hairy, and lateral face-marks reduced to dots; flagellum Hght orange 

 beneath in both sexes (South Boulder Canyon, many at fls. Grindelia, Aug. 9, T. 



&= W. Ckll.) ignota Ckll. 



No doubt many more species of Perdita will eventually be foimd in Boulder county. 

 P. punctata (Ckll.) and P. rectangulata Ckll. occur at flowers of Solida^o at Ft. 

 Collins, 



GREELEYELLA CockereU 



Female about 9 mm. long, brown-black, very shiny; two submarginal cells; mar- 

 ginal cell broadly obliquely truncate; first recurrent nervure meeting, or almost 

 meeting, first transverso-cubital; male -with broad head and light yellow clypexis 

 (Boulder, fls. Malvastum, June, W. P. Ckll.) beardsleyi Ckll. 



NOMADA Fabricius 



Abdomen chestnut red, without light bands I. 



Abdomen with conspicuous light bands 4. 



