OF THE AMAZON VALLEY. 519 



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 tibiae 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 Thyriclia. In Thyridia the lower disco-cellular is short and straight, and 

 placed at an obtuse angle with the median, whilst the middle disco-ceUular 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 31. Psidii. Like the other 

 species of the genus, its flight is somewhat slow and heavy. It frequents thinned parts 

 of the virgin forest, moving about the lower trees and underwood. It differs from 

 M. Fsidii, 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 (PL 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 Linnseus 

 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 coIotu? of the thorax varies in almost every specimen. lii all there is 

 a round grey spot on the wing-lappets ; but in som.e 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. Felder's specimens came from the Upper Hio Negro. It is distinguishable 

 from M. Psidii at once by its structural generic characters, as wiU be seen from the 

 description above given of the genus Methona ; but in size and colours the two resemble 



VOL. XXIII. 1 A 



