226 HYMENOPTERA ACULEATA. 



abdomen even in fresh examples has no white pubescent 

 spots. 



L. 5-6 mm. 



Not so common as morio, but widely distributed. It 

 occurs in Scotland, but I have uo Irish record. 



ANDRENA, Fab. 

 This genus is the ricliest in species of all the British 

 genera of the Anthophila ; its characters are fairly well 

 defined, although some of the species superficially resemble 

 Halictus. J narrower and often smaller than the $ ; tongue 

 lanceolate, paraglossaj obtuse, labial palpi with four cylin- 

 drical joints, maxillary palpi six-jointed, submentum hyaline, 

 lora distinct, head in the ^ often very large, usually larger 

 than in the ? , but often variable in size in the same species ; 

 ? with an impression on the inner side of each eye towards 

 the vertex, filled with velvety pubescence; anterior wings 

 with three submarginal cells ; abdomen with seven dorsal 

 segments exposed in tbe St six in the ? , the sixth with a 

 distinct dorsal area ; six ventral segments exposed in the 

 ?, eight in the S , although the seventh is almost entirely 

 hidden under the sixth. The ^ armature affords hardly 

 any specific characters among closely-allied species, the 

 stipites as a rule are dilated and converge to the apex, 

 there is no distinct lacinia, and the sagittEe are narrow and 

 pointed ; sting of the ? feeble ; both sexes have a patella on 

 the posterior tibioe, which in the ? also bear a well-developed 

 scopa, and are slightly dilated ; the posterior coxae bear 

 a tuft of curled hairs called ih.eJloccus, which is often a 

 prominent character. The most important structural cha- 

 racters in the c? seem to occur in the labrum, clypeus, the 

 relative lengths of the second, third, and fourth antennal 

 joints, the general puncturation, and the form of the eighth 

 or terminal ventral segment ; in the $ , in the shape of the 

 face, the puncturation, and the sculpture of the apical dorsal 



