LETTERS FROM ALABAMA. 
205 
I have also obtained some very fine moths : the 
Green Emperor [Saturnia luna) is a very remark- 
able as well as beautiful species. It is large, mea~ 
snring nearly five inches in breadth; the wings 
are of a pale pea-green, with a half-shut eyespot in 
each; the hind pair are elongated into a long tail- 
like process, as in the swallow-tailed butterflies, 
which extends more than an inch and a half from 
the outline of the wing. An eminent naturalist 
observes, that the lower wings of the Lepidop- 
tera, when thus unusually lengthened, perform the 
same office in flight as the tail does among birds, 
for we find that all the swiftest flying butterflies 
have what are aptly and justly called swallow- 
tailed wings.^^ I am not aware, however, that the 
present species affords any exception to the gene- 
rally heavy flight of the thick-bodied family to 
which it belongs : the specimen which has come 
under my notice was particularly slow and tame 
(although a male), but as both the tailed processes 
were much shortened by being weather-beaten, it 
would not be fair to dravr a conclusion from it 
alone. I suppose, without breeding the insect 
from pupa, it would be rare to meet with a perfect 
specimen, these long tails being, from their fragile 
nature, particularly liable to injury. 
Two specimens of another species of the same 
genus, the Corn Emperor {Saturnia /o), were 
.lately given to me ; one of which flew into a house 
in the evening, the other was flying in the shade 
of a large tree in the middle of the day. Both 
are females; they are four inches and a half in 
extent ; the fore wings dark red, with two dusky 
bands ; the hind wings yellow, with two concentric 
semicircular bands, the outer red, the inner black, 
