318 CIHARLES ROBERTSON. 



almost impuiictate, apical margins of segments narrowly testaceous, the whole 

 with close whitish pubescence, except discs of first and second ; wings white, 

 hyaline, nervures very pale; tegulse honey-yellow. Length 5 — 6 mm. 



% . — Eesembles the female ; mandibles at tips, antennse beneath, knees and 

 tarsi, testaceous. Length 5 mm. 



Hub. — Illinois; ten 9 , one % specimen. 



Halictus tegularis 9 • — Head and thorax dark gi-een, sometimes with a 

 brassy reflection, abdomen brown; flagellum at tip beneath, testaceous; meso- 

 thorax rather strongly and closely punctured ; metathorax rounded, not strongly 

 truncate, the disc with irregular rugte not reaching posterior margin ; abdomen 

 shining, thinly clothed with pale pubescence, apical margins of segments more 

 or less testaceous; wings hyaline, nervures honey-yellow; tegulse large, black, 

 pubescent, strongly punctured. Length 4.5 — 5.5 mm. 



% . — Resembles the female, abdomen more strongly punctured, antennse testa- 

 ceous beneath. Length 4 mm. 



Hab. — Connecticut, District of Columbia, Illinois, Montana, Cali- 

 fornia, Mexico ; thirty-one 9 , two % specimens. Easily distin- 

 guished by its small size and strongly j)unctured tegulap. 



Prosopis iielumbonis 9 • — Head and thorax closely punctured with 

 coarse shallow punctures; clypeus long, finely roughened, with shallow depres- 

 sions ; base of metathorax rough, with coarse reticulations ; abdomen impunc- 

 tate, smooth and shining, especially the first segment. Insect black, clothed 

 with a thin whitish pubescence; triangular mark on each side of face, tubercles 

 and spot on tegulae in front, yellow ; abdomen with the first and base of second 

 segment rufous; legs black, base of tibiae yellow, extending to the middle on 

 posterior pair; hind tarsi fulvous. Length 6.5 mm. 



Hab. — Illinois. Four specimens, taken on flowers of Xymphcea 

 reniformis and Nelmnbo lutea. 



