satisfactory if these apparent inconsistencies could be lucidly explained. If, however, it be ultimately proved that _Sphecodes_ is a constructive bee, as well as _Prosopis_, we have then this fact exhibited by our native genera, that none of the subfamily of our short-tongued bees, or _Andrenidæ_, are parasitical. This is a remarkable peculiarity, as it is amongst them that we should almost exclusively expect to find that distinguishing economy, from the seemingly imperfect apparatus furnished in the short structure of their tongues. It is possible, however, that nature has so moulded them as to fit them chiefly for fulfilling its objects within merely a certain range of the floral reign, and which restricts them to visiting flowers which do not require the protrusion of a long organ to rifle their sweet stores. Genus 4. ANDRENA, _Fabricius_. (Plates II. and III.) MELITTA ** _c_, Kirby. _Gen. Char._: HEAD transverse, as wide as the thorax; _ocelli_ in a triangle on the vertex; _antennæ_ filiform, geniculated, the basal joint of the flagellum the longest; _face_ flat; _clypeus_ convex, transverse, quadrate, slightly rounded in front; _labrum_ transverse, oblong; _mandibles_ bidentate; _tongue_ moderately long, lanceolate, fringed with fine hair; _paraglossæ_ half the length of the tongue, abruptly terminated and setose at the extremity; _labium_ about half the length of the entire apparatus, its inosculation acute; _labial palpi_ inserted above it, below the origin of the paraglossæ in a sinus upon the sides of the tongue; _maxillæ_ irregularly lanceolate; _maxillary palpi_ six-jointed, longer than the maxillæ, the basal joint about as long as the fourth, but more robust, the second joint the longest, the rest declining in length and substance. THORAX ovate; _prothorax_ not distinct; _mesothorax_ quadrate; _bosses_ protuberant; _scutellum_ lunate; _post-scutellum_ lunulate; _metathorax_ gibbous, and pubescent laterally; _wings_ with three submarginal cells, and a fourth slightly commenced, the second quadrate, and with the third receiving a recurrent nervure about their middle; _legs_ densely pubescent, especially externally, and particularly the posterior pair, which have a long curled lock upon the trochanter beneath, the anterior upper surface of the femora clothed with long loose hair, which equally surrounds the whole of the tibiæ, but which is less long upon their plantæ, the _claws_ strongly bifid. ABDOMEN ovate, a dense fringe edging the fifth segment, and the terminal segment having a triangular central plate, its sides rigidly setose. The MALE differs in having the _head_ rather wider than the thorax, the _vertex_ where the ocelli are placed more protuberant, the _mandibles_ very large and more acutely bidentate, sometimes largely forcipate and with but one acute tooth; the males in most species greatly differ from their females.