228 INSECTS. 



inch in length, H. morio (PI. IX., fig. 2), an exceedingly 

 abundant species, is one-sixth and over. This last is a 

 beautiful little glossy black creature with somewhat of a 

 metallic lustre ; other species are more or less clothed 

 or banded with white, grey, or golden hairs, while some 

 are entirely black. The males have long slender bodies 

 and long antennas. It is worth noticing that in this and 

 the preceding genus, the wing-hooks, instead of forming 

 a series, arranged at regular, or regularly decreasing in- 

 tervals, as in the generality of Bees (see fig. 24, p. 50), 

 are interrupted and placed thus 



Fig. 60. 



C = 



a. Hooks of posterior wing of Sphecodes rufescens. 



b. do. do. of S. subquadratus. 



c. do. do. of Halictus morio. 



The examination of a large number of species might 

 possibly prove this to afford a character useful in the 

 distinction of species. The fore-wings have three sub- 

 marginal cells. 



The females of the genus Andrena may be recognised 

 without difficulty by a beautiful little tuft of curled hairs 

 on the underside of the trochanter of the hind-legs (see 

 fig. 57, 1, p. 222). Being an instrument for conveying 

 pollen, it is more conspicuous in the females than in the 

 males, but these also have a tuft of hairs in the same 

 position. 



