62 A COLONY OF ANTHOPHORA 



number of cells varies from five or six up to ten 

 or eleven. 



Anthophora pilipes has a very close relative 

 in Anthophora retusa, which, also forms large 

 colonies, but it is as a rule less common. These 

 two species are exceedingly alike, in fact it 

 requires some skill on the part of the observer 

 to differentiate their females. They are both 

 black and clothed with black hairs, and both 

 have yellow pollen-brushes, but in retusa the 

 hairs are shorter and not quite of such a deep 

 black as those of pilipes, and the spurs of the 

 tibiae are pale, whereas in pilipes they are black. 

 The males, however, differ widely, although 

 much alike in colour ; in pilipes the feet of the 

 middle pair of legs are clothed with enormously 

 long hairs, the basal joint has a dense fringe of 

 black hairs in front and some long black hairs be- 

 hind (see pi. D, fig. 24) ; in retusa the basal joint 

 of the middle pair of feet have a fan-shaped fringe 

 of black hairs, and the rest of the joints are clothed 

 with longer hairs, but not long enough to be 

 specially noticeable. A. retusa is visited by the 

 same cuckoo as A. pilipes and also by its rare ally 

 Melecta luctuosa, which only differs from armata 



