170 
LETTERS FROM ALABAMA. 
there is also an intermediate row of azure fascia. 
The anterior margin of the fore wings is unusually 
curved, causing these wings to assume a rounded 
form. This fine insect is not noticed by Abbott, 
nor is a yet nobler species, the Yellow Emperor 
Swallowtail {PapiUo Thoas)^ which measures, when 
expanded, five inches and a-half. The ground 
colour of this is black, with a very broard macular 
band of buff-yellow, crossing the base of the hind 
wings, and running on to the tip of the fore wings; 
there is a similar band likewise common to both 
pairs, which follows the course of the outer margin 
at some distance from it. The tails are yellow, 
with a black border. Beneath, the ground is yel- 
low, on which the nervures are broadly traced in 
black, and three or four similar black lines run 
along the middle area of the fore wing ; a narrow 
black band crosses both pairs near the outer mar- 
gin, containing a series of azure crescents in the 
hind pair. The contrast between the prevailing 
colours of the upper and under surface is very 
observable, as the insect floats carelessly along, 
slowly flapping its voluminous wings, or rests half 
expanded to sip the slushy mud in the stable-yard: 
when it has a magnificent appearance. It seems 
to be rare, as I have seen but a single specimen. 
Boisduval gives a figure of its larva, which is of 
large size, and, from a singular distribution of its 
colours, reminds one of a piebald horse. The tints 
are arranged in about seven large patches, — two 
white, four black (viz. two on each side), and a 
large brick-red one behind the head. I have never 
met with it myself, and know not its food. 
From the largest of our butterflies, I come, by 
a contrast quite unintentional, to speak of the very 
