Studies of North American Bees 85 



black without .a tinge of red, and other differences. From A^, 

 vinnnla Cresson, it differs in smaller size, lack of yellow on 

 supraclypeus, posterior orbits and propodeum black, much 

 smaller pleural spot, wings not distinctly apically darkened, lack 

 of black bands on venter, etc. Of the other Washington species 

 of this subgenus (see Psyche, XVII, p. 98), it differs from N. 

 mutans Ckll., at once in the bright lemon yellow maculations, and 

 is much too small to be the unknown female of A^. hcsperia Ckll. 



Nomada (Holonomada) snowii Cresson. 



i8f8. Nomada snozini Cresson, Trans. Am. Ent. Soc, VII, p. 75, ? c?- 

 1903. Nomada snowii Cockerel!, Proc. Acad. Nat. Sci. Phil., p. 609, ?. 

 1905. Nomada snowi Cockerell, Bull. 94, Colorado Exp. Sta., p. 72, 



A female from Custer, South Dakota, agrees exactly with 

 .Cresson's description of his unique type female from Colorado, 

 except that the third antennal joint is quite distinctly longer 

 than the second, and the writer does not feel justified in referring 

 this specimen elsewhere than to snozcii. Cockerell (/. c.) places 

 sjiozi'ii in the subgenus Micrononiada from Cresson's description, 

 but Cresson says nothing about the presence of spines on the 

 anterior coxae. A female from Valley City, North Dakota, 

 August 13, 1912, on Grindclia (O. A. Stevens, No. 3575) re- 

 sembles the Custer specimen except that the first abdominal tergite 

 is black and has a broad, complete white band, the clypeus and 

 supraclypeus are yellow, slightly suffused with reddish marginally, 

 and the mesopleura have larger white L-shaped spots and little 

 or no red color. The recently described .V. iiinitans Ckll. is allied, 

 resembling snoivii in the creamy white maculations, but snowii 

 differs from it in the opaque, cancellately punctured mesoscutum, 

 entirely red legs except for the creamy spots, large L-shaped 

 pleural spot, etc. V. vicrecki Ckll., which also has creamy 

 maculations, has coxal spines and therefore belongs to 

 Micrononiada. 



Nomada (Holonomada) besseyi n. sp. 



c?. Length 9 mm. Deep black ; large triangular lateral face marks with 

 digitate extensions along orbits nearly to their summits, two lateral oblong 

 clypeal spots, labrum basally, collar, tubercles, a broad transverse bar 



85 



