Feb., '07] ENTOMOLOGICAL NEWS. 57 



15. Perdita melanostoma n. sp. 



$. Length, 5.5 mm. Head dark green, changing to greenish blue on 

 occiput and cheeks, and to deep black on the clypeus, the mesonotum 

 aeneous green, with remainder of thorax deep blue. Usually a round 

 yellow spot on each side of clypeus, and mandibles more or less com- 

 pletely yellow. Antenna- brownish black, the flagellum yellowish be- 

 neath. Levs black, with all the knees, first four tibiae in front, and the 

 anterior tarsi, yellow. A small spot on tubercles, whole of tegulse and 

 bases of the wings yellow. Wings clear, nervures blackish, stigma 

 brownish fuscous. Abdomen black, the middle of segment i and ba-es 

 of 2-4 with broad, narrowly medially interrupted or notched, transverse 

 yellow bands. Venter fuscous. Cheeks, mesonotum. pleura, legs, last 

 two abdominal segments above, and whole of venter with peculiar, 

 sparse, very erect, bristle-like and heavy, pure white pubescence, long 

 only on abdomen tip and posterior legs. 



c?. Unknown. 



T\ pe : Glen, Sioux County, Nebraska, August 19, 1906, on 

 Gitticrrczia sarothrae (P. R. Jones), 9 . 



Paratypes: 25 9 9 from type locality, August 18-22, 1906, 

 on Guiicrrczia sarothrae. 



This species runs out near P. snbfasciata and sphacralccac, 

 but is neither; the former has the whole head and thorax dark- 

 bluish green, almost black, and the mandibles wholly dark, and 

 flies at flowers of Chrysothammts. 



16. Perdita luteola Cockerell. 



Thirty-eight females and nineteen males. August 12-22, 1906, 

 on Gnticrrczia sarothrae at Glen, Sioux County, Nebraska. 



17. Perdita perpallida Cockerell. 



The co-types of this species, taken at Neligh, Nebraska, in 

 July (M. Gary), at flowers of Pctalostcuwn violacens, are the 

 only specimens so far captured. 



18. Perdita wootonae Cockerell. 



This species flies in abundance in northwest Nebraska, visit- 

 ing exclusively the flowers of Nuttalia nnda from July 28 to 

 August 22. A series of over 250 specimens from Crawford 

 and ( ilcii shows that the male is dimorphic, some specimens hav- 

 ing very small, round, unarmed heads, while others have enor- 

 mous, heavy heads with strong cheek spines. These two ex- 

 tremes intergrade. The type of wootonae has black tarsi, but 

 this character is variable and all the Xebraska specimens ex- 

 amined have the tarsi pale. The pleural spot is also variable 



