OF THE AMAZON VALLEY. 
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terminates on the outer margin; the lower disco-cellular is placed at a right angle with 
the median, is much longer than the middle disco-cellular (which is straight), and 
strongly angulated. The fore legs of the male have the tibia? and tarsi linear in shape, 
although much shorter than the femur ; they differ in length in individuals of the same 
species, but are never so far aborted as to form a mere round knob at the tip of the 
femur, as in Thyridia. In Thyridia the lower disco-cellular is short and straight, and 
placed at an obtuse angle with the median, whilst the middle disco-cellular is very long 
and angulated; and the internal (abdominal) nervure is short, terminating on the 
abdominal border. 
1. Methona Themisto, Hiibner. 
Thyridia Themisto, Hiibn. Zutrag. f. 163-4. 
I found this species at Para, where it was associated with M. Psidii. Like the other 
species of the genus, its flight is somewhat slow and heavy. It frequents thinned part- 
of the virgin forest, moving about the lower trees and underwood. It differs from 
M. Psidii, principally, in the absence of a black belt across the disk of the hind wings. 
It is probably a modification of it. 
2. Methona Psidii, Linnaeus (PI. LVI. fig. 8 a). 
Papilio Psidii, Linnaeus, sec. Cramer. 
— , Cram. Pap. Exot. t. 257, f- F. 
• Mr. Doubleday and all subsequent authors have considered the P. Psidii of Linnaeus 
and Cramer to be a Thyridia. I cannot imagine how their mistake has arisen, all the 
numerous examples of the insect represented by Cramer as P. Psidii which I have 
examined having the wing-neuration and male fore legs of Methona. It is an 
exceedingly common insect throughout the Amazon region. The figure of Cramer is 
accurate : the small, rounded shape of the hyaline area near the tip of the hind wing, 
crossed by two nervures only, and the opake black colour of the basal part of the hind 
margin of the fore wing reaching the median nervure (both good specific characters), are 
well given. The colour of the thorax varies in almost every specimen. In all there is 
a round grey spot on the wing-lappets ; but in some examples the edges of these organs 
are also grey, and in others the surface of the thorax is much variegated with grey colour. 
Genus Thyridia (Hiibner), Doubleday. 
Doubld. and Hewits. Gen. Diurn. Lep. p. 117- 
Thyridia Ino, Pelder. 
Thyridio Ino, Feld. Wien. Ent. Monatschr. 1862, p. 75 
I found this species at Villa Nova, on the Lower Amazons, in company with Methona 
Psidii Dr Pelder's specimens came from the Upper Rio Negro. It is distinguishable 
from M. Psidii at once by its structural generic characters, as will be seen from the 
description above given of the genus Methona ; but in size and colours the two resemble 
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