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. 1. _aterrima_, Panzer, ♂ ♀. 4-4½ lines. _punctulatissima_, Kirby, 2. _phæoptera_, Kirby, ♂ ♀. 4-4½ lines. (Plate XI. fig. 3 ♂ ♀.) 3. _octomaculata_, Smith, ♂ ♀. 3 lines. GENERAL OBSERVATIONS.