Dec, 1907.] Crawford : Notes on Halictus. 183 



Sphecodosoma pratti, new species. 



9 . — Head and thorax black, shiny, abdomen dark red ; pubescence sparse, 

 rather long, glistening white ; head elongate, facial quadrangle slightly longer than 

 wide ; eyes narrow, inner orbits straight parallel ; head almost impunctate ; clypeus 

 produced, with a few punctures ; mandibles red, bases black ; antennae clavate, funi- 

 cle reddish below, scape reaching about one half way to ocelli ; mesothorax slightly 

 lineolated, scutellum more plainly so, both finely sparsely punctured more closely so 

 at posterior edges; median and parapsidal grooves apparent but not deep; meta- 

 thorax basally with fine rugulas not reaching to apex, leaving a smooth shiny margin; 

 truncation smooth, not surrounded by a carina ; mesopleurce smooth, indistinctly 

 lineolated, metapleurse distinctly so; tegula; large, shiny, black inwardly, the rest 

 translucent ; wings dusky, nervures and stigma dark brown ; third submarginal nar- 

 rowed one half to marginal ; legs black, femora robust, pubescence glistening white ; 

 first segment of abdomen black at base, smooth, sparsely punctured, remaining seg- 

 ments sparsely punctured, finely lineolated ; pubescence on fifth segment at apex, 

 sooty brown. Length 4 mm. 



$. — Similar, antennse not clavate, reaching almost to metathorax, more yel- 

 lowish below, abdomen black. Length 4 mm. 



Locality. — CotuUa, Texas, May 10, 1906, on Marilaunidium 

 organifoliiim (F. C. Pratt and J. C. Crawford colls.). 



Type. — No. 10050, U. S. National Museum. 



It resembles the genus Proteraner in that both sexes come out at 

 the same time in the spring, which is not the case in the other forms. 



NOTES ON SOME SPECIES OF THE GENUS 

 HALICTUS. 



By J. C. Crawford, 

 Washington, D. C. 



The species included in this paper are those which have no green 

 on them and which are found in the United States and Canada. In 

 using the table it will be necessary to consult the detailed descriptions 

 of the species before one can be certain of the identifications, since 

 there are still many undescribed forms in North America. 



Table for the Females. 



1. Apical margins of abdominal segments with hair bands ; none of the wing veins 



obsol escent : 2 



No hair bands on apical margins of segments ; some of the wing veins obso- 

 lescent 5 



2. Cheeks armed with a strong spine ligattis Say. 



Cheeks not armed 3 



