GENERAL OBSERVATIONS.
It is difficult to assign a reason for the name of this genus, or to trace an applicable derivation from ἐπίαλος, for the insect in no way suits, either directly or by anti-phrase, any of the significations of this word. It is one of the prettiest of our little bees, and is parasitical upon the Colletes Daviesiana, and it may be found in abundance wherever the metropolis of this species occurs. There is one special locality near Bexley, in Kent, a vertical sandbank within a few hundred yards of the village, where I have always found it in the spring months, and have there taken it as numerously as I wished. I have already alluded, in another part of this work, to the uniformly greater beauty of the parasitical bees, to those which they infest, and their exceedingly different appearance in every case excepting in that of the genus Apathus. We might have expected that they would have been disguised like these, the better to carry on their nefarious practices, but what can well be more dissimilar than Epeolus and Colletes, or than Nomada and all its supporters, and the same of Melecta, Cœlioxys, and Stelis. These facts puzzle investigation for a reason; nor will the perplexity be speedily solved. All that we can surmise is that there must be a motive for it, for wherever we successfully elicit her secret from the veiled goddess, we invariably find the reason founded in profound wisdom. In some cases the mystery seems devised to test our sagacity, but it cannot be so here, for the most palpable and plausible cause that would suggest itself in the supposition of its being for the guardianship and apprisal of the sitos is often contravened, as in this instance, by it and its parasite living in great harmony together, again by the desertion of its nidus by Eucera in favour of the parasite, although itself is a very much more powerful insect; but in the cases of Panurgus, Halictus, and Andrena, they all live well reconciled to the intrusion of the stranger’s young, and this, without their enumeration, may be adopted as nearly the universal case. The hostility of Anthophora, previously noticed, is an almost insulated case of the contrary. The form of these insects does not promise much activity, and we accordingly find that they are slow, heavy, and indolent; yet they must be cautiously handled, for they sting acutely; but indeed it is not well ever to handle insects whose markings, as we find them in these, consist of a close nap, as evanescent as the down upon a plum, and of course the fingers carry it readily off, and disfigure the beauty of the little specimen. When their special habitat is not known they may often be found upon the blossoming Ragwort in the vicinity, or upon the Mouse-ear Hawkweed (Hieracium murorum) within whose flowers they are frequently observed enjoying their siesta.
b. With two submarginal cells.
Genus 17. Stelis, Panzer.
([Plate XI.] fig. 3 ♂ ♀.)
Apis ** c, 1 β, Kirby.
Gen. Char.: Body glabrous, much punctured. Head transverse, curving posteriorly to the thorax, where it is angulated laterally; ocelli in a triangle at the summit of the vertex; antennæ short, slender, filiform, scarcely geniculated, the scape about as long as the three first joints of the flagellum, all the joints of which are subequal but slightly increasing in length towards the apical one, which is a little compressed laterally; face entirely flat; clypeus transverse, rather convex; labrum elongate, convex; mandibles robust, tridentate, the external tooth considerably the stoutest; cibarial apparatus long, tongue three times as long as the labium, slightly inflated in the centre, and terminating in a small knob; paraglossæ very short, not more than one-sixth the length of the tongue and acuminate; labial palpi about two-thirds the length of the tongue, the two first joints membranous, the basal one the most robust, and both tapering to an acute apex, shortly before which the two very short subclavate terminal joints articulate; labium about one-third the length of the tongue, its inosculation trifid, the central division considerably the longest and truncated at its extremity; maxillæ subhastate, nearly as long as the tongue, acutely acuminated towards their apex; maxillary palpi very short, two-jointed, the basal joint subclavate and slightly the longest, and inserted in a circular cavity, the terminal joint short ovate. Thorax subglobose; prothorax inconspicuous; mesothorax very convex; scutellum lunulate, very gibbous, and impending over the post-scutellum and metathorax, mucronated laterally; metathorax abruptly truncated; wings with two submarginal cells, and a third very slightly commenced, the two subequal, the second being the largest and receiving the first submarginal cell near its commencement and the second at the inosculation of the terminal transverso-cubital nervure; legs short, moderately stout, the tibiæ very slightly setose externally; claws short, bifid, the internal tooth near the external. Abdomen oblong, truncated at its base, very convex above and flat beneath, deflexed towards its extremity, and the terminal segment almost rounded, being very slightly produced in the centre and margined.
The MALE scarcely differs, excepting in the usual male characteristics, and by the apical segment being obsoletely tridentate.
NATIVE SPECIES.