•2\)4 PROCEEDINGS OF THE \\ll<>\\l MUSEUM, vol. 38. 



The apical joint of the male antennae is not dilated in the triangu- 

 lifera or nevadensis group. The inclosure of the mfetathorax in 

 N. triangulifera is boat-shaped, more or less narrowed in the middle. 

 The tegulse in the female are variably infuscated, whereas in all 

 members of the nevadensis group they are pellucid rufotestaceous. 



The only species of this group is Nomia triangulifera Vachal, 1897 

 (persimilis Cockerell 1898), found in Nebraska, Kansas, and New 

 Mexico. It is the type of Ashmead's genus Epinomia. 



GROUP OF XOMIA BETEROPODA (DIEUNOMIA). 



Very large s])eeies; abdomen black, without iridescent bands; 

 males with apical joint of antennae swollen, and middle femora 

 greatly swollen, the hind legs also much modified, the hind basitarsus 

 extremely long. 



(A) Wings uniformly dark fuliginous. 



Nomia heterojxxhi Say. A female from Victoria, Texas, at flowers 

 of Helta nth us, October 2, 1904 (J. C. Crawford, collector), is referred 

 here. 



(B) Wings hyaline, orange- tinted, with the apical margin very 

 broadly fuliginous. 



Nomia apacha Cresson. I refer here two females from Victoria, 

 Texas, at flowers of HeUantlms,( Vtober 2, 1904 (A. J. Leister, collector). 

 1 am at some disadvantage with regard to this and the last species 

 from having only females (the male of apacha is unknown), and from not 

 having authentic material for comparison; I have seen the species, 

 however, in the Cresson collection, and the present specimens accord 

 very well with my notes and recollections. The apacha and Ketero- 

 poda were taken at the same place, on the same day, at Helianthus, 

 and appear to be identical except for the very different coloration 

 of the wings. Is it possible that they are two forms of a single 

 specie- '. 



N. apacha is known to be western (Colorado, New Mexico), while 

 A'. Ittttrojxx/a is eastern (Texas to Arkansas and Maryland): do 

 they meet at Victoria, Texas, and possibly hybridize? There is 

 apparently a problem here calling for field investigations. 



From the other specie-, with similarly colored wings, X. apacha is 

 readily known by the combination of strongly fulvous pubescence 

 on the thorax above with light fulvous tegulse and a very black. 

 unhanded, abdomen. 



X marginipt nnis ( Iresson. A female before me is from Rocky Ford, 

 Colorado, collected by Prof. C. P. Gillette. 



Vomia xerophila Cockerell. MesillaPark and Aztec, New Mexico; 



Sterling, Colorado (S. A.Johnson, collector) ; MoabUtah, "S. 10/06" 



I L.S. National Museum). In the male.it is the fourth ventral segment 



which is elevated at the lower lateral cornel's, and the fifth which 



