MACROPIS. 223 



drenidae, especially in the form of the abdomen and of 

 the intermediate and posterior legs, as well as in the 

 length of the claws and the low insertion of the posterior 

 joints of the tarsi upon their plantse, a peculiarity not 

 occurring in another genus of the Andrenidae. 



I have no doubt, also, that they are very musical in 

 their flight and are, perhaps, as shrill-winged as is Sa- 

 ropoda ; whereas one of the great characteristic specia- 

 lities of the Andrenidee is their silence. This genus, 

 although restrained within the circuit of the subnormal 

 bees by the structure and folding of its tongue, has so 

 much of the habit of one of the true Apidce that it al- 

 most prompts the wish to resuscitate the circular systems 

 and place it within its own circle in analogical juxtapo- 

 sition to Saropoda in the circle of the Apida, where 

 they might impinge one upon the other. It is not often 

 that so rare an insect is at the same time so curious 

 and so suggestive. Having been found, there is no 

 reason why it may not be again found with due and 

 patient diligence ; my own experience has taught me 

 how easy it is even in well-hunted ground to make 

 rarities common, within almost a stone's throw of the 

 metropolis, at Hampstead, Highgate, and Battersea, 

 from which localities in the course of my entomological 

 career I have introduced to our fauna many novelties, 

 one of which was certainly a remarkable discovery, 



v v J 



from the last spot named, which it is worth recording. 

 A quantity of soil had been removed from the City 

 where an artesian well was being bored, and consequently 

 from varying depths, and carted thence and cast upon 

 the edge of the river-bank at Battersea. The following 

 season, from this soil, a thick and prodigious quantity of 

 the common mustard plant shot up, and when in flower 



