74 
DIPTERA, 
It may be fafely handled— The plate is B. medius — 
laid to hover in the air like a hawk ; and dart 
with great celerity* B . viajor is called Humble 
Bee-Fly* 
GENUS to.—H IPPOBOSCA, HORSE- 
LEECH. 
. * * * .*.*!* "*1 
The Hippobofcae have been called by fome authors 
fpider-flies, from the refemblance which fome of them 
bear to that infeft, others have called them horfe- 
Jlies j by which name they are more generally 
known. 
They are found frequently in woods and marfhy 
places ; but moft commonly on the bodies of birds ; 
thofe of horfes and other quadrupeds ; fucking their 
blood, upon which alone they fubfift. 
Their larvae are unknown. One fpecies is known 
to be pupiparous ; the egg being larger than the mo¬ 
ther ; and is rathei: a pupa or chryfalis, than a real 
egg, fmce the compleat or winged infe6t is produced 
from it. 
Hippobofca Equina. 
'Received from the New Foreft, in Hampfhire, 
where numbers pf them live, and riot upon horfes and 
cattle. They are very hard to kill, being covered 
with a hard cruftaceous fhell ; and they fix fo clofe 
and fall fo the poor animals, with their claws, that 
,; they 
% 
