§§§§ _Thorax very pubescent, abdomen smooth and shining._
45. _albicans_, Kirby, ♂ ♀. 4-5 lines. 46. _pilipes_, Fabricius, ♂ ♀. 5-7 lines. _pratensis_, Kirby. 47. _cineraria_, Linnæus, ♂ ♀. 5-7 lines. (Plate II. fig. 2 ♂ ♀.) _cineraria_, Kirby. 48. _thoracica_, Fabricius, ♂ ♀. 5-7½ lines. _thoracica_, Kirby. _melanocephala_, Kirby. 49. _nitida_, Fourcroy, ♂ ♀. 5-6½ lines. (Plate II. fig. 3 ♂ ♀.) _nitida_, Kirby. 50. _vitrea_, Smith, ♀. 6½ lines.
§§§§ _The entire body densely pubescent._
51. _fulva_, Schrank, ♂ ♀. 4-6½ lines. (Plate II. fig. 1 ♂ ♀.) _fulva_, Kirby. 52. _Clarkella_, Kirby, ♂ ♀. 4½-6½ lines.
Fabricius seems to have named this genus from _ανθρήνη_, _a wasp_, but why, it is impossible to say. Although one name is as good as another, it being indifferent what the name may be, yet where so evident an attempt to give a name pertinence is conspicuous, it is remarkable that it should be so little relevant, for none of the characteristics of a wasp or hornet are exhibited in these insects.
Possibly it was from the genus being the most numerous in species that Dr. Leach was induced to give this subfamily its collective designation, making the other genera thus converge to it as to a centre. He took its elliptical form as typical. Indeed, it is remarkable how very judiciously this was done, for it is a form not apparent among the normal bees excepting in two exceptional cases, the one upon the frontiers of this subfamily, in almost debatable land, where the last of the _Andrenidæ_ and the first of the _Apidæ_ seem almost to melt into one another; and in the other case, in the parasitical _Nomada_, whose parasitism is in every instance, but one only, restricted to the first subfamily. A different type of form prevails amongst the _Apidæ_, upon which I shall have subsequently occasion to speak.
These insects are not distinguished for any elaborate economy. Varying in the species, some prefer vertical banks, others sloping undulations, and again others horizontal flat ground or hard down-trodden pathways. Some burrow singly, and others are gregarious, collected in great numbers upon one spot. They are, perhaps, the most inartificial burrowers of all the bees. Their tunnels vary from five to nine or ten inches in depth, and in some species they are formed with other small tunnels slanting off from the main cylinder. The sides and bottom are merely smoothed, without either drapery or polish. The little cells thus formed are then supplied with the usual mixture of pollen and honey kneaded together, which in the larger species forms a mass of about the size of a moderate red currant, its instinct teaching it the quantity necessary for the nurture of the young which shall proceed from the egg that it then deposits upon this collected mass of food. The aperture of each little tunnel is closed with particles of the earth or sand wherein the insect burrows, and it proceeds to the elaboration of another receptacle for a fresh brood until its stock of eggs becomes exhausted. Some species have two broods hatched in the year, especially the earlier ones,—for several present themselves with the earliest flowers,—but others are restricted to but one. The quantity of pollen they collect is considerable, and in fact they are supplied with an apparatus additional to what is furnished to any of the other genera in a curled rather long lock of hair that emanates from the posterior trochanters. This, with the fringes that edge the lower portion and sides of the metathorax, as well as the usual apparatus upon the posterior legs, enables the insect to carry in each flight home a comparatively large quantity of pollen, but perhaps scarcely enough at once for the nurture of one young one, and it therefore repeats the same operation until sufficient is accumulated.