262 BRITISH BEES. 



b. With two sulmarginal cells. 



Genus 17. STEMS, Panzer. 



(Plate XI. %. 3 ? .) 



APIS ** c, 1 /3, 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 ; antenna short, slender, filiform, scarcely 

 geniculated, the scape about as long as the three first 

 joints of the flagellum, all the joints pf which are sub- 

 equal 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; paraglossa 

 very short, not more than one-sixth the length of the 

 tongue and acuminate ; labial palpi about two-thirdi 

 the length of the tongue, the two first joints membra- 

 nous, 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 trun- 

 cated at its extremity ; maxilla 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 



