British Hymenoptera. 211 



11. Halictns cijlindricus, Fab. 



Fab., Ent. Syst. ii., p. 302 ; Smith, Cat. Brit. Hym., 

 2nd ed., p. 87. 



Black ; head and thorax sparsely clothed with brown 

 hairs ; metathorax, viewed from in front, sharply trun- 

 cate, its angles slightly refiexed. Abdomen in the <? 

 elongate, generally more or less red ; in the ? oval. 

 Apical margins of the segments in both sexes widely pale ; 

 the 2nd, 3rd, and 4th segments in the ^ and the 2nd 

 and 3rd in the ? with a lateral basal spot of white 

 pubescence. 



(? . Head and thorax closely punctured ; face elon- 

 gate ; eyes converging considerably towards the cly]ieus ; 

 mandibles divided from the eyes by a narrow cheek. 

 Clypeus produced, sharply truncate in front, with a large 

 pale spot at the apex ; face below the antennte covered 

 with white hairs. Antennae reaching to about the end of 

 the metathorax. Thorax with the puncturation more 

 distant than that of the head. Wings almost clear ; 

 nervures brown ; metathorax, viewed from in front, 

 sharply truncate behind, its apical margin refiexed near 

 the lateral angles ; viewed from above, with a somewhat 

 triangular clathrate basal area. Abdomen shining, elon- 

 gate, shallowly punctured ; 1st, 2nd, and 3rd segments 

 often more or less red at the sides and apex. Apical 

 margins testaceous : 2nd, 3rd, 4th, and often 5th, seg- 

 ments at the base with a lateral white pubescent spot. 

 Abdomen above with a few scattered brown hairs, beneath 

 glabrous, nearly flat; (for genitalia see pi. ix., fig. 1). 

 Legs black ; the base and apex of the tibiae and the tarsi 

 pale ; the apical joints of the latter brownish. 



? . Head and thorax finely and closely punctured, 

 clothed with brown hairs ; inner margins of the eyes 

 converging slightly towards the clypeus ; metathorax as 

 in the ^ , but with its basal area semicircular. Abdomen 

 oval, slightly wider than the thorax ; basal segment very 

 shining, clothed with scattered brown hairs at the base 

 and sides, but glabrous on the disk and apex ; the surface 

 sparsely and very shallowly punctured, the following seg- 

 ments duller and clothed with a short brown pubescence, 

 forming a distinct band at the apex ; the 2nd and 3rd 

 segments with a white lateral pubescent streak at the 

 base ; 5th densely clothed with golden brown hairs. 



