v] BEES 67 



upwards above its thorax. I can offer no explanation 

 of this peculiarity. 



The Halicti are also burrowing bees, frequenting 

 banks, sandy places on heaths, hard gravel paths and 

 similar situations ; and often forming large colonies. 

 They are moderately hairy ; most are dark in colour 

 with narrow bands or spots of whitish hair on the 

 abdomen, which is not so flattened as in the Andrenas. 

 Some however have a bright brown and smooth 

 abdomen, and a few are of a bronzy green colour. 



Fig. 12. Last segment of abdomen of female Halictus, 

 showing the ridge ("rima") characteristic of females 

 of this genus. 



Some of the smallest of our British bees are included 

 in this genus, several species of Halictus being less 

 than a quarter of an inch in length. The female 

 Halicti can readily be distinguished by the possession 

 of a very well-marked ridge (the rima) along the 

 centre of the back of the fifth segment of the abdo- 

 men ; the sixth segment is hardly visible, so that the 

 "rima" appears to be on the terminal segment (see 

 fig. 12). The sting is too feeble to penetrate the 

 human skin. The various species are to be found in 



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