Vili PLAN OF THE WORK. 
guage, such as are used in other departments of human 
knowledge, 
Tn consequence of the materials which I was obliged 
to use, I have not succeeded altogether according to 
my wishes, in simplifying the following descriptions ; 
but I trust there are so few of the stumbling blocks left, 
that the student may easily surmount them. 
The groundwork of the description of British but- 
terflies and moths was first laid by Mr. Haworth, who 
has certainly not been surpassed in minute accuracy by 
any of his followers, most of whom have borrowed 
largely from him without acknowledgment. I owe him 
my best thanks for the loan of the third part of his 
valuable work, (now out of print, and very scarce,) 
which he most liberally granted through the medium of 
my friend Mr. Loudon, the distinguished author of 
what I always call the miraculous “ Encyclopedia 
of Plants.” The materials taken from this part are 
uniformly marked by inverted commas; but I deem 
it due to the author to state, that even where these 
marks do not occur, by far the larger portion of this 
little volume is a free translation from his Latin. 
Next to Mr. Haworth, I haye been indebted to the 
works of Mr. Stephens, more particularly his “ Syste- 
matic Catalogue,” the names and order of which I 
have, with a few exceptions, implicitly followed; and 
I cannot too strongly recommend every person engaged 
in the study of British insects to procure a copy of this 
