NO. 1852. BEES OF THE GENUS NOMADA—COCKERELL. 237 



it was described as a variety semirufula. The present insect repre- 

 sents another variety, more approaching N. sulphurata, but it does 

 not seem worth while to give it a special name. It seems that sul- 

 phurata of the Eastern States, perivincta of the Rocky Mountains, and 

 citrina of the California region are very closely allied, and possibly 

 only subspecifically distinct. They are all confusingly variable. 



NOMADA ACCEPTA Cresson. 



A male in Baker's collection labeled "Colo. 1160" was marked 

 accepta by Baker, but someone crossed this out. It differs from 

 Cresson's description of male accepta as follows: Upper half of la- 

 brum and base of mandibles broadly, cream-color; tubercles with a 

 large cream-colored spot; pleural patch red with a large transverse 

 cream-colored mark. I possess only the female of N. accepta, but 

 after careful comparisons I feel assured that the male is correctly 

 referred to it, the various differences noted being due to variation. 

 In my table of Rocky Mountain Nomada ^ this runs to the same place 

 as the female. The mesothorax and metathorax are entirely black. 



NOMADA (MICRONOMADA) VEGANA Cockerell. 



Six from the Baker collection from Colorado, with numbers 1591, 

 2325, 2096, 2098, 1081. 



NOMADA CIVILIS Cresson. 



A male from West Cliff, Colorado (Cockerell); marked fragilis by 

 Ashmead, and recorded as such.^ 



NOMADA FRAGILIS Cresson. 



Several males from Fort Collins, Colorado, 1905, collector unknown; 

 one from Baker, labeled "Colo. 2212." 



NOMADA (NOMADULA) ARTICULATA DACOTANA Cockerell. 



Males; Colorado (Baker 2076); Denver, Colorado, May 23, 1898 

 (collector not given). 



NOMADA (NOMADULA) MARTINELLA Cockerell. 



Male: Berkeley, Colorado, May 18, 1898 (collector unknown). 



NOMADA (NOMADULA) FRIESEANA Cockerell. 



Male. — Length 10 mm.; superficially like N. articulata dacotana, 

 with the same red, yellow-banded abdomen, but the light band on 

 first segment with a spot on each side, and the apical plate entire; it 

 is easily distinguised by the antennas, which are thick, with the fourth 

 joint much shorter, the fifth with a prominent sharp spine; the tegulse 



1 Bull. 94, Colorado Agric. Exper. Station. s Trans. Amer. Ent. Soc, vol. 20, p. 339. 



