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XX. Oh the Insect called Oistros by the Ancient Greeks, and Asilus 
by the Romans. By William Sharp Mac Leay, Esq., M.A. F.L.S. 
Communicated by the Zoological Club of the Linnean Society. 
Read March 16, 1824. 
Tux determination of the animals and plants mentioned by the 
ancient writers must always be a pleasing subject of research, 
tending, as it does, not merely to our better comprehension of the 
meaning of these authors, but also to our better acquaintance 
with the mysteries of nature. Every classical reader, as well as 
every entomologist, is familiar with the word Oestrus as the name 
of one of the most celebrated insects of antiquity. The insect 
itself, however, 
* cui nomen Asilo 
* Romanum est, Œstron Graii vertere vocantes,” 
VIRG. Georg. iii. 147. 
has not for this been the more accurately determined ; and Oli- 
vier is the first modern naturalist who appears to have suspected 
that the Œstrus of the ancients and the Œstrus of the moderns 
are totally different insects. With an exception in favour of 
Messrs. Latreille, Kirby and Spence, this curious remark seems 
not to have excited much attention; although it may easily be 
proved, that Olivier has come much nearer the truth than those 
who hold the contrary opinion. 
In investigations of the following nature, it is not only advan- 
tageous but necessary to begin from some fixed and indisputable 
position. Now such I take to be the identity of the insects 
termed in French taon; in Spanish tavano; in Italian tabano ; 
and 
