CocCKERELL : NortTH AMERICAN SPECIES OF HyMENOoxys 509 
and Perdita chrysophila Ckll., visits H. floribunda at Pecos, N. M. 
The latter observation is due to my wife. 
UNIVERSITY OF COLORADO, 
ULDER, COLORADO. 
Explanation of plates 20-23 
PLATE 20. Hymenoxys floribunda utilis 
PLATE 21, FIGURE 1. Aymenoxys Earlei. 
PLATE 21, FIGURE 2. Hymenoxys latissima. 
PLATE 21, FIGURE 3. Aymenoxys Metcalfei. 
PLATE 22, FIGURE I. Hymenoxys WU 
PLATE 22, FIGURE 2. Aymenoxys oliv 
PLATE 22, FIGURE 3. Aymenoxys iota oushougts excurrens. 
PLATE 23, FIGURE 1. Aymenoxys pheno: spans 
PLATE 23, FIGURE 2. Hymenoxys chrysanthemoides Mea 
All of the figures are from photographs of the ee specimens. 
