28 BRITISH BEES. 



or prominent ridge, down its centre, lies between these 

 eyes, descending from the vertex to the base of the cly- 

 peus, or nose, but which is without the function of that 

 organ. This clypeus is sometimes protuberant, and from 

 shape or armature, characteristic. This part, however, is 

 not always distinctly apparent, although a line or suture 

 usually separates it above, from the face. At its lower 

 extremity the labrum, or upper lip, articulates, over 

 which it is sometimes produced ; and it extends at each 

 lateral apex to the base of the insertion of the mandibles. 

 The genm, or cheeks, descend from the vertex laterally, 

 behind the compound eyes, to the cavity of the head 

 which contains the lingual apparatus, when folded in re- 

 pose. These cheeks, at their lower extremity, sometimes 

 embrace the articulation of the mandibles. 



The antenruB, or feelers, are two filamentary organs 

 articulating on each side of the face and above the cly- 

 peus. They comprise the scape (a), or basal joint, and 

 [b] the flagellum ov terminal apparatus; the latter con- 

 sists of closely attached conterminal joints, and usually 

 forms an elbow with the scape; collectively these joints 

 number twelve in the female and thirteen in the male. 

 They are all of various relative lengths, which sometimes 

 . aid specific determination. The scape, how- 

 ^psoa^za ever, is usually much longer than any of the 



^'^ 1 rest, and in some males has a very robust and 

 even angulated shape. A description of the 



^'"^'■^ antennae always enters into the generic charac- 



2 \ ter ; they usually differ very materially both in 



Fig. 6.— 1. length and form in the sexes. They are often 



tennil m' filif°™ (2), but more generally subclavate (1), 



lifoi-m ditto; and sometimes distinctly so, and where they 



d, scape > Oj .. * 



flagellum. have the latter structure it is found in both 



