30 
BRITISH BEES. 
tlie gullet and assists deglutition; the labium, or lower 
lip, and the true tongue. These parts are all single; 
the parts in pairs are the mandibles, the maxillae, the 
maxillary palpi, the labial palpi, and the paraglossae. 
The labrum, or upper lip, is attached by joint to the 
apex of the cly- 
peus; it has a ver¬ 
tical motion, and 
falls over the or- 
Z..J gans beneath it, 
in repose, when it 
is itself covered 
bv the mandibles. 
It is usually trans- 
, , verse in form, but 
Fig. 7.—Tropbi and their unfolding, a, labrum ; 
b, epipharynx; c, pharynx ; d, hypophaiynx; e, man- IS sometimes per- 
dible ; f, maxillae; g, maxillary palpi; h, mandible; • •. 
i, cardium; k, labium; l, labial palpi; m, paraglossae; pentllCUlar, espe- 
7i, tongue. cially in the ar¬ 
tisan bees. It takes many forms, sometimes semilunar 
or linear, emarginate or entire, convex, concave, or flat, 
and is occasionally armed with one or two processes, 
like minute teeth projecting from its surface, but of what 
use these may be we do not know. In the female of 
Halictus, it has a slightly longitudinal appendage in the 
centre. It is usually horny, but is sometimes coriaceous 
or leathery. This labrum often yields good specific cha¬ 
racters. 
The pharynx, or gullet, is a cavity immediately be¬ 
neath the epipharynx, which articulates directly under 
the base of the labrum, and which closes the pharynx 
from above, and immediately beneath this cavity is 
another small appendage, almost triangular, which re¬ 
ceives the food or honey from the canal conveying it 
