26 HYMENOPTERA. 



Halictus atricornisj n. s. 



Black and shining, the wings siibhyaline, palest at their 

 base. 



Female. — Length 3 lines. — Head very closely and finely 

 punctured, sub-opaque ; the clypeus porrect, shining, and with 

 a few large elongate punctures. Thorax shining and finely 

 punctured above, with a faintly impressed central longitu- 

 dinal line, and an abbreviated one on each side near the 

 tegulsB ; the tegulse slightly piceous at their outer margin, the 

 metathorax at its base above rather finely rugose, the rugosity 

 somewhat longitudinal ; the wings clouded and iridescent, 

 becoming paler towards their base; the legs have a pale 

 glittering pubescence; the spurs at the apex of the tibiae are 

 pale, and the claw-joint of the tarsi rufo-piceous. Abdomen 

 ovate and shining, very finely and distantly punctured, ex- 

 cept the basal segment, which is very glossy and im punctate, 

 or with only a few fine punctures towards the apical margin. 



Male. — Length 2| lines. — The colour and sculpturing 

 atyreeins: with that of the other sex ; the antennae as long as 

 the thorax; the apex of the clypeus with a transverse white 

 spot. The wings iridescent, clouded as in the other sex ; 

 the four apical joints of the tarsi rufo-testaceous ; the abdo- 

 men elongate-ovate, very smooth and shining. 



This species in general aspect resembles Halictus villosulus 

 in the female sex; the species are about the same size, but 

 the strong puncturing of the thorax of H. villosulus at once 

 separates them ; then it also resembles II. minuta, but it is 

 more robust in form, the clypeus more produced, the wings 

 clouded to their margins, and the rugose space at the base of 

 the metathorax is not enclosed behind by a shining ridge ; 

 the antennae in both sexes are entirely black; in H. ininutus 

 they are pale beneath, and this species has a shining ridge 

 that encloses the rugose space on the metathorax behind, and 



