PROC. ENT. SOC. WASH., VOL. 20, NO. 8, NOV. 1918 179 



thorax, with a punctureless area on each side of middle posteriorly; the 

 clypeus and supraclypeal area are also highly polished, with very few punc- 

 tures. From H. supercretus Ckll. it differs by the shining thorax, white 

 bands on abdomen, clearer wings and other characters. The tegulae are 

 piceous; area of metathorax granular, not sharply bounded behind; pos- 

 terior truncation with long, pale hair, not sharply margined; hair of head 

 and thorax white; abdomen subglaucous, extremely finely punctured, hind 

 margins of segments not pallid; stigma rather dull ferruginous. 



Tlahualilo, Durango, Mexico, at peach blossoms March 9. 

 1904 (A. W. Morrill'). U. S. Nat, Museum. 



Halictus respersiformis sp. n. 



Female. Length about 6 mm., anterior wing 5 mm. ; robust, black, with 

 black legs, antennae and tegulae, but hind margins of second and following 

 abdominal segments broadly dark brown; pubescence dull white, the bases 

 of second and third abdominal segments with large elongate patches of 

 white tomentum on each side, the base of fourth with white hair right 

 across, but thin in middle; head suboval, face narrow; front extremely 

 densely and minutely punctured; mesothorax shining, but finely and closely 

 punctured all over, on the disc posteriorly the punctures separated by more 

 than the diameter of one; area of metathorax minutely reticulated, with 

 delicate oblique plicae at sides, the posterior middle V-shaped, not crossed 

 by a sharp keel; posterior truncation heart-shaped, sharply defined, with 

 long hair not hiding the surface; tegulae reddish-black; wings strongly 

 dusky, stigma and nervures dark brown, second submarginal cell rather 

 broad, receiving first recurrent nervure well before end; hind spur with 

 three long teeth, all far from base; abdomen shining, with thin pale hair, 

 first segment very minutely punctured, principally at sides, toward the 

 base very finely transversely lineolate. 



Tlahualilo, Durango, Mexico, at peach blossoms, March 9. 

 1904 (A. W. Morrill) U. S. Nat. Museum. In Crawford's table 

 (1907) this runs to H. macoupinensis Rob. and H. divergens Lov- 

 ell, but it is larger and more robust than these, with dark tegulae. 

 In the Mexican fauna it resembles H. respersus Vachal, but is dis- 

 tinguished by the reticulate area of metathorax and dusk}' wings. 



Halictus cordovensis sp. n. 



Male. Length about 6 mm., anterior wing 4.7 mm.; black, the abdomen 

 shining, reddish black; pubescence scanty, white, rather abundant on face, 

 but not hiding surface; head round seen from in front, face broad, clypeus 

 not produced; no pale face-marks; mandibles chestnut-red apically; an- 

 tennae long, black; clypeus closely punctured; front granular under a 

 lens, but the microscope shows rather coarse punctures, so dense as to give 

 a cancellated effect; mesothorax coarsely and very densely punctured, a 



