564 MR. H. W. BATES ON THE HELICONIDE LEPIDOPTERA 



8. EuEiDES Aliphera, Godart. 



Papilio Aliphera, Godt. Encyclopedie Methodique, t. ix. p. 246. 



A widely distributed species, being found over nearly the whole of tropical America. 

 It seems to be constant throughout. I met with it at St. Paulo. 



Subfamily ACR^IN^. 

 Genus Acb^a, Fabricius. 

 1. AcB^A Thalia, Linnaeus. 

 Papilio Thalia, Linn. Syst. Nat. ii. 757, n. 67. 



, Cramer, Pap. Exot. t. 246. f. A. 



I took (at Para) only one individual of this sole species of Acriea found in the Amazon 



EXPLANATION OP THE PLATES. 



The Plates are designed to show a few examples out of a great number of mimetic analogies between 

 various Lepidopterous insects and the Heliconidse. The insects figured belong to four families, very 

 widely dissimilar in structure and metamorphosis : Leptalis (fam. Pierids), DiojMs (Bombycida;, Moths), 

 Stalachtis (fam. Erycinidae), Ithomia, Mechanitis, Methona (fam. Heliconidre). The figures also illustrate 

 the process of the origination of a mimetic species through variation and natural selection. Reasons have 

 been given (p. 504 et seq.) for considering the species of Leptalis and Dioptis, amongst others, as having 

 been adapted by this process to the species of Stalachtis and the genera of Heliconidae — the colours being 

 brought into exact resemblance by the successive preservation of such naturally arising variations as 

 tended more and more to resemble. One species only, Leptalis 7%eowoe, furnishes a good example of the 

 process, it being one which, by a rare chance, shows in its existing varieties the process in different stages 

 of completion. The figures indicated by a simple numeral represent the adapted forms ; those marked a, 

 the species to which they are adapted. 



Plate LV. 



Fig. 1*. Leptalis Theonoe (Hewitson). — Inhabits Cupari, 55° W. long. 



Fig. la. Ithomia Flora (Cramer) .—Inhabits Cupari, 55° W. long. ; also the mouth of the Amazons and 



Surinam. 



Neither of these forms is found further westward on the Upper Amazons, where the following 



allied species and varieties alone occur. 

 Fig. 2. Leptalis Theonoe, var. Melanoe. — St. Paulo, Upper Amazons, 69° W. long. 

 Fig. 2a. Ithomia Onega (Hewitson). — Upper Amazons, from 58° to 70° W. long. 



* The specimen of L. Theonoe in the British Museum collection, which served Mr. Hewitson for his figure of the 

 species, is very much larger than the one figured in this Plate. But the Leptalides are apt to vary very much 



