Cuap. VIII. SAND WASPS. 195 
of the Dragon-flies (whose early states are passed in the water) to those 
of Britain. A species of Libellula with pointed tail, which darted about 
over the bushes near the ponds, is very closely allied to our English 
L. quadrimaculata. But the resemblance was greater in the small, 
slender-bodied and slow-flying species, the Agrions, which every lover 
of rural walks must have noticed in England by river sides. There 
was one pretty kind, with a pale blue ring at the top of the body, which 
resembled to a remarkable degree acommon British species. Although 
very near akin, neither this nor any of the other kinds were perfectly 
identical with European ones. ‘The strikingly peculiar dragon-flies 
from Tropical America which are seen in our collections are denizens 
of the forest, being bred in the shady brooks and creeks in their recesses, 
and not in the weedy ponds of open places. Some of these forest 
species are strange creatures, with slender bodies measuring seven inches 
in length ; their elegant lacework wings tipped with white or yellow. 
They fly slowly amongst the trees, preying on small Diptera, and in 
their flight look like animated spindles ; the wings, placed at the fore 
extremity of the long, horizontally-extended body, moving rapidly and 
creating the impression of rotary motion. 
Whilst resting in the shade during the great heat of the early hours 
of afternoon, I used to find amusement in watching the proceedings of 
the sand wasps. A small pale green kind of Bembex (Bembex ciliata) 
was plentiful near the bay of Mapiri. When they are at work, a number 
of little jets of sand are seen shooting over the surface of the sloping 
bank. The little miners excavate with their fore feet, which are 
strongly built and furnished with a fringe of stiff bristles; they work 
with wonderful rapidity, and the sand thrown out beneath their bodies 
issues in continuous streams. They are solitary wasps, each female 
working on her own account. After making a gallery two or three 
inches in length, in a slanting direction from the surface, the owner 
backs out, and takes a few turns round the orifice, apparently to see 
whether it is well made, but in reality, I believe, to take note of the 
locality, that she may find it again. This done, the busy workwoman 
flies away ; but returns, after an absence varying in different cases from 
a few minutes to an hour or more, with a fly in her grasp, with which 
she re-enters her mine. On again emerging, the entrance is carefully 
closed with sand. During this interval she has laid an egg on the 
body of the fly, which she had previously benumbed with her sting, and 
which is to serve as food for the soft footless grub soon to be hatched 
from the egg. From what I could make out, the Bembex makes a 
fresh excavation for every egg to be deposited ; at least, in two or three 
of the galleries which I opened there was only one fly enclosed. 
I have said that the Bembex on leaving her mine took note of the 
locality : this seemed to be the explanation of the short delay previous 
to her taking flight ; on rising in the air, also, the insects generally flew 
round over the place before making straight off. Another nearly allied, 
but much larger species, the Monedula signata, whose habits I observed 
on the banks of the Upper Amazons, sometimes excavates its mine 
solitarily on sandbanks recently laid bare in the middle of the river, 
and closes the orifice before going in search of prey. In these cases 
