190 THE ENTOMOLOGIST. 



The advantages of this notation are that it can be easily 

 written in the text, and conveys at once to the eye the ancestry 

 and constitution of the form before us. 



NEW AND LITTLE-KNOWN BEES FROM NEBRASKA. 



By T. D. a. Cockerell. 



The following bees were kindly communicated to me by Mr. J. 

 C. Crawford, Jun., and Prof. L. Bruner : — 



Perdita affinis, Cresson. — West Point, Aug. 12th, 1900 (J. C. 

 Crawford). Both sexes at flowers of Solidago rigida. New to 

 Nebraska. 



Perdita albipennis, Cresson. — Lincoln, Aug. 17th, 1900 

 (J. C. Crawford). Both sexes at flowers of Helicmthus 

 annuus. 



Perdita hrimeri, Ckll.— West Point, Aug. 6th, 1900 (J. C. 

 Crawford). Two females at flowers of Grindelia ; one is larger 

 than usual. 



Perdita perpallida, n. s-p. — Lehigh, July (Gary). Both sexes 

 at flowers of Petalostemon. 



Length about 6 mm., very pale yellowish, colour of P.ivootontc, but 

 without any black patch on pleura in either sex. Female with legs 

 entirely pale, but male with a large black patch on inner side of 

 anterior femora beueatb. Male flagellum pale orange, not marked 

 with black above. Stigma very pale yellow, nervures colourless. 

 Abdomen entirely without bands. Ocelli black, but no black lines on 

 vertex in either sex. 



Perdita crawfordi, n. sp. — Lincoln, Nebr., Aug. 25th, 1900 

 (J. C. Crawford). Male at sunflower ; female at Grindelia. 



$ . Length about 5 mm. ; head and thorax dark bluish green ; 

 head ordinary ; cheeks with a short tooth on lower part ; front, vertex 

 and cheeks with short white hair ; vertex minutely granular ; antennae 

 dark brown above, very pale beneath ; clypeus and lateral face-marks 

 cream-colour ; clypeus wholly pale except the usual dots ; lateral 

 marks transversely oblong, not quite reaching the level of the upper 

 edge of the clypeus, the inner side bulging above, and thus larger than 

 that adjacent to the eye ; no supra-clypeal or dog-ear marks ; thorax 

 rather abundantly clothed with white hairs ; no light markings on 

 prothorax or pleura; wings milky-hyaline; nervures white, stigma 

 faintly yellowish ; marginal cell nearly squarely truncate, the sub- 

 stigmatal portion about as long as the post-stigmatal ; second sub- 

 marginal cell greatly narrowed above ; third discoidal cell only faintly 

 indicated ; legs black, knees, anterior tibiae in front, and the tarsi, pale 



