OF THE AMAZON VALLEY. 539 



The species of Ithomia are very numerous ; 107 liave already been described, but many 

 still exist unpubbshed in collections. They are most numerous in the equatorial parts of 

 America, decreasing towards either tropic. One only is found in the West India Islands, 

 and none, I believe, in extra-tropical North America. Two or three occur in 30° S. lat. ; 

 but the genus is unknown in Chili and to the south of the Rio de la Plata. Most of 

 the species have curiously limited ranges ; many of those inhabiting the banks of the 

 Upper Amazons do not extend more than 100 or 200 miles, although there are no apparent 

 physical barriers to their dissemination ; and it is probable, from the number of new ones 

 received in collections made in newly explored localities, that most of the Andean valleys 

 have their peculiar species. 



They are prolific insects, and gregarious in their habits, flocks of many diiferent species 

 associating together. Their flight is low and weak ; and they affect only certain parts of 

 the forest, generally shady hollows, where many hundreds may often be seen sporting 

 together, although not an individual is found in any other part of the neighbourhood. 



1. Ithomia Eukimedia, Cramer. 



Papilio Eurimedia, Cram. Pap. Exot. t. 126. f. C, D. 



■ ^gle, Hiibner, Samml. Ex. Schm. 



A common species at Para and throughout the Lower Amazon region. It is often found 

 in company with Leptalis Eumelia, to which it has so great a resemblance that the two 

 seem to be of the same species when on the wing. It is found also at Surinam (in com- 

 pany with the Leptalis) ; and I have examples from Bahia, in S. E. Brazil, where a variety 

 of it also occurs which is widely disseminated over South and extra-tropical Brazil. 



2. Ithomia Nise, Cramer. 



Papilio Nise, Cram. Pap. Exot. t. 231. f. E. 



Selene, Cram. Pap. Exot. t. .315. f. F, G. 



Neso, Hiibn. Samml. Ex. Schm. 



Cramer's figures of this species are very bad ; but I think they are recognizable with 

 the assistance of the descriptions in the text, and that they represent the same species as 

 that figured hj Hiibner under the name of Neso. It is an abundant species at Para, but 

 is not found anywhere else in the Amazon region. I have specimens of both sexes from 

 Demerara, and find that they do not diflPer from Para examples ; at Cayenne, however, a 

 local variety prevails in which both wings have above a submarginal row of pale spots, 

 and the general colour is much paler. It is the only Ithomia known to me in which the 

 sexes are strikingly different in appearance. The wings of the c? are more transparent, 

 and much paler in colour that those of the $ , especially the discal area of the hind wing. 

 The peculiar texture of the surface of the wings is owing to the extreme fineness of the 

 scales with which they are covered. I consider I. Azara (Hewits. Exot. Butt. Ithomia, 

 f. 23), which occurs on the banks of the Napo, a local modification of this species, several 

 connecting forms being known. The very beautiful lolaia (Hewits. I. c. f. 97) of New 

 Granada is probably also another local variety *. 



* I. Tutia, Hewits. Exot. Butt. Ithomia, ii. 6 (a species allied to /. Nise), is given as an Amazonian species 

 erroneously. It is a native of Venezuela. 



