MACROPIS. 
223 
drenida, 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 plantm, a peculiarity not 
occurring in another genus of the Andrenidce. 
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 Andrenidts 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 Apidce , 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, 
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 
