70 
HOW TO COLLECT 
G ASTRO PH 1LUS EQUI. 
“ (Estrides (Bot- and Gad-, or Warble-flies) 
are sa id to hover over mountain-tops. Hypoderma, 
however, is generally to be taken sitting on 
bare sunny places, in roads, heaths, etc. Gas- 
trophilus is often to be seen round horses, and 
may sometimes be taken with a net; but it may 
be noted that it is labour wasted to attempt to 
catch specimens of this genus with a white net. 
Cephenomyia sits on stones in spots frequented by deer, and is said 
to settle not infrequently on human beings who enter its haunts. 
“ Muscidoe Acalypteratce are to be taken as a rule 
by sweeping, though a few Ortalidce, Micropezidce, 
Trypetidce, etc., may be captured on leaves and flowers, 
trypkta coknuta. as well as on carrion and oiduie. 
“ Ollier Families. —As regards other families, many of them will be 
met with while seeking for those already mentioned ; and though the 
habits, etc., of the remainder are as varied as in the case of the latter, 
still the specimens encountered fortuitously will probably mount up 
to a considerable number.” 
Method of Collecting. 
If possible, Diptera should always be brought home alive in the 
glass-bottomed pill-boxes (to which they are to be transferred on 
being captured in the net), and should then be killed in the cyanide- 
bottle or jar immediately before being pinned. As soon as a fly is 
taken in the net by a dexterous sweep, a sharp turn of the wrist 
must be given (following a smart downward or lateral stroke in 
order to bring the fly to the end of the net), in such a way that the 
end of the net containing the insect falls over the rim and so makes 
a closed bag from which it cannot escape. The end of the net can 
then be gathered up in the hand, and the fly forced into a still 
smaller space, in which it will not he difficult to get it into a pill-box, 
and then to slip on the lid. If the specimens are small, it is possible 
with care to get several into one pill-box. Flies may also be 
transferred direct from the net to the killing-bottle, and so brought 
home dead; but this method is not to be recommended, since prolonged 
exposure to the effects of cyanide of potassium is apt to injure the 
