208 THE ENTOMOLOGIST. 



H. olympia CklL, has a very large second submarginal, so 

 that the third, though large, is not much bigger. Spur 

 coarsely serrate. 

 H. Olympics subangustiis, CklL, has the third submarginal es- 

 sentially of the short type, but there is more or less of a 

 double curve. Spur serrate. 

 H. kincaidii, CklL, has a strong double curve, but third sub- 

 marginal hardly of the long type. Spur with few long teeth. 

 H. angustior, CklL, has the third submarginal essentially of 

 the narrow type, but almost or quite twice as large as the 

 small second submarginal. Spur with about four oblique 

 teeth, the first quite long. 

 The following species (not including those enumerated by 

 Robertson) have the third submarginal undoubtedly as in Lasio- 

 glossum : — 



American. European. 



imcijicus, CklL vulpinus, Nyl. 



sisymhrii, CklL major, Nyl. 



similis, Smith. malachurus, Kirby. 



politus, Smith (Mexico), leucozonius, Schrank (but cell very 



calceatus, Scop. [large). 



Certain of these, as H. pacijicus, sisymhrii, leucozonius, and 

 calceatus, have the spur coarsely serrate as in H. coriaceus. 

 H. politus, which looks much like these, has the spur with numer- 

 ous moderately long teeth. H. similis has the spur with about 

 four short oblique slender teeth. 



The greatest reduction of spur-teeth I have seen results in 

 the hind edge of the spur being apparently simple, but a high 

 power lens shows it to be minutely beaded. This occurs in the 

 American H. amicus, CklL, and the European H. zonulus, Smith. 

 Halictus (Lucasius) cochlear citar sis, Dours, has the third sub- 

 marginal long, but there is hardly any double curve, and the 

 angle is slightly appendiculate. This is a large black species 

 with continuous hair-bands on abdomen ; spur with teeth quite 

 large towards the base, otherwise minute. 



Nomioides is a genus of little bees with nearly the structure of 

 Halictus, but all the form and colours of Perdita. N. variegatus, 

 Oliv., and N. pidchellus, Schenck, have the third submarginal 

 short, but slightly angled outwardly, and minutely appendiculate. 

 Ashmead is wrong in treating Lucasius as a synonym oi Nomioides, 

 as Mr. Vachal has pointed out to me. 



Mr. Vachal writes me that Thrinchostoma, Sauss., "is an 

 Halictus, with the tongue longer than in Halictus s. str., and 

 bodkin-shaped. The name of Saussure's genus is wrongly spelled 

 by Dalla Torre and Ashmead. 



East Las Vegas, New Mexico, U.S.A. : 

 May 9th, 1903. 



