214 
BRITISH BEES. 
Section 2. With entire paraglossce. 
Subsection c. Lingua acuta: (acute tongues), 
a. With three submarginal cells to the icings. 
Genus 6. Halictus, Latreille. 
(Plate IV.) 
Melitta b, Kirby. 
Gen. Char.: Head transverse, flattish, scarcely so 
wide as the thorax; ocelli in an open triangle on the 
vertex, which is flat; antennce short, filiform, genicu- 
lated, scape quite or more than half as long as the fla¬ 
gellum; face flat, excepting in the centre just below the 
insertion of the antennae, where it is protuberant; clypeus 
transversely lunulate, very convex; labrum subquadrate, 
very convex, with a central, linear, carinated appendage 
in front, nearly as long as the basal portion; cibarial 
apparatus moderate; tongue very acute and delicately 
fringed with short hair; paraglossee acute, about half 
the length of the tongue; labial palpi not quite so long 
as the paraglossse, the basal joint very long, the rest 
decreasing gradually in length ; labium about as long 
as the tongue, its inosculation emarginate; maxillce 
subhastate, rather longer than the tongue; maxillary 
palpi filiform, the basal joint the shortest, second the 
longest, the rest decreasing in length. Thorax oval, 
usually pubescent, sometimes glabrous; prothorax in¬ 
conspicuous, as are the bosses of the mesothorax; scutel- 
lum and post-scutellnm lunulate, the former convex; 
metathorax gibbous or truncated, but laterally pubescent 
even in the glabrous species; wings with three submar¬ 
ginal cells, and a fourth sometimes commenced, the se¬ 
cond subquadrate and receiving the first recurrent nervure 
close to its extremity, the second being received beyond 
