BEES OF GREAT BRITAIN. 



39 



18. Halictus leucopus. 



H. viridi-aeneus, abdomine nigro. Mas, antennis subtus fulvis ; 

 tar sis albidis. 



Melitta leucopus, Kirby, Mon. Ap. AngL ii. 59. 18 $ . 

 Halictus leucopus, Smith, Zool. vi. 2101. 7 $ ? . 

 Nyland. Ap. Boreal, p. 247. 23. 



Female. Length 3 lines. He*ad and thorax dark green, the 

 clypeus slightly produced; the flagellum testaceous beneath. 

 Thorax shining ; the tegulse testaceous ; the wings hyaline, iri- 

 descent, the nervures pale testaceous ; the legs have a glitter- 

 ing white pubescence, that on the tarsi beneath pale fulvous. 

 Abdomen very glossy at the base, the apical margins of the 

 segments rufo-piceous, and having a scattered pubescence 

 towards the apex ; sometimes a little white pubescence at the 

 lateral basal margins of the second and third segments. B.M. 



Male. Head and thorax bright green, the apex of the clypeus, 

 labrum and mandibles pale yellow ; the flagellum pale fulvous 

 beneath. Thorax : the tegulse rufo-piceous ; the wings hyaline, 

 splendidly iridescent ; all the tarsi and the base of the tibiae pale 

 yellow, the claws ferruginous. Abdomen black, elongate-ovate, 

 thinly covered with short griseous pubescence ; the apical 

 margins of the two basal segments depressed. B.M. 



This species is not so abundant as the two preceding, but is 

 widely distributed ; the female is so like to that of aneus, that it 

 becomes difficult to point out a distinctive difference ; the form 

 of the head is perhaps the best and most obvious difference, it is 

 much rounder, and the clypeus scarcely produced ; the disk of 

 the thorax is more strongly and not so closely punctured; 

 the males are easily distinguished by the colouring of the tarsi. 

 I possess specimens taken " in coitu," or I could not have felt 

 certain of the sexes, although I had strong suspicions pre- 

 viously. These small species of Halicti are difficult to separate, 

 and require attentive study and observation. 



Div. III. Entirely black the first recurrent nervure uniting 

 with the second transverse cubital nervure. 



19. Halictus longulus. 



H. niger, pubescentia rufo-testacea, abdomine elongato. 

 Female. Length 4 lines. Black, head and thorax very closely 



