HYMENOPTERA. 665 



distinctly from the wasps and the digger-wasps, which pro- 

 vision their nests with other insects or with spiders. 



The superfamily Apina includes two families : the An- 

 drenidae or short-tongued bees, and the Apidae or long- 

 tongued bees. These can be separated as follows : 



A. Bees with the terminal portion of the lower lip, the glossa, flat- 

 tened and shorter than the mentum ; and with the basal segments 

 of the labial palpi not unlike the following segments, p. 665. 



ANDRENID^E. 



AA. Bees with the glossa slender, not flattened, and longer than the 

 mentum ; and with the basal segments of the labial palpi elongate. 

 p. 666 APID^E. 



Family ANDRENIDAE (An-dren'i-dae). 

 The Short-tongued Bees. 



The family Andrenidae includes several genera of bees 

 which agree in having the glossa shorter than 

 the mentum, and flattened (Fig. 794). In 

 some genera the glossa is spear-shaped, in 

 others it is heart-shaped. 



The different genera of this family vary 

 greatly in habits, but none of the species are 

 social. Among the more common short- 

 tongued bees are some that make their nests 

 in the ground, and on this account are termed 

 mining-bees. It should be remembered, how- 

 ever, that some of the Apidae are also mining- 

 bees, and that not all of the Andrenidae are FIG. ^.- 



of Sphecodes. m, 

 miners. mentum; f. pal- 



The nest o f a mining-bee usually consists 

 of a tunnel, more or less branched, each branch leading to 

 a single cell. The walls of these cells are glazed, appearing 

 like the surface of earthenware. In each cell there is stored 

 a quantity of pollen and nectar-paste, an egg is laid with 

 this food, and the cell is then closed up. 



Among the larger of our common mining-bees are those 



