OF THE AMAZON VALLEY 



497 



This view of the affinities of the family will make a great difference in the conception 

 of the group as regards the affiliation of the forms. Instead of heing a group isolated in 

 its structure, and peculiar to the tropical parts of America, it results that the hulk of the 

 genera have a very close relationship to the Danaidce, which are found in all hot countries 

 of both hemispheres : the Acrceoid JTeliconidce alone are an isolated set of forms. The 

 American productions, however, show a great superiority in structure and in the diversity 

 of the forms over those of the Old World. In Africa only one genus occurs, namely, 

 Danais. In the tropical parts of Asia four genera are found, besides Danais ; these are 

 Ideopsis, Sestia, Euplcea, and Hamadryas, which contain together 74 species. In the 

 hot parts of America 16 genera (of Dmiaoid Seliconidce) have been discovered, comprising 

 233 described species. Besides this greater diversity of generic and specific forms, the 

 American productions show a much greater advance in organization than those of the 

 Old World ; in other words, they recede further from what may be considered as the 

 common type, namely, Danais. This is clear from the great and progressive modification 

 in the position of the radial nervures and discocellulars of the hind wings, and the 

 advanced stage of atrophy of the male fore legs reached by most of the genera. In all 

 the Asiatic genera the fore legs are in the same condition as in Danais and the Nym- 

 phalid(B. The following Table will show the relative value of the productions of the two 

 hemispheres in a clearer manner. I have placed the genera in accordance with what 

 seem to be their mutual affinities. The relative length of the lines between them is 

 a rough expression of the degree of relationship. The collateral lines of connexion are 

 also attempted to be expressed. 



Asia. 

 Danais (31 sp.) 

 Ideopsis (2 sp.) I 



I Euploea (58sp.) 



Hestia (12 sp.) 



Hamadryas (2 sp.) 



DaNAIDjE. 



Africa. 

 Danais (10 sp.) 



America . 

 Danais (8 sp.) 



Dan aotd Heliconid.i;. 



Lycorea (6 sp.) 



Ituna (3 sp.) 

 Methona (3 sp.) 



Thyridia (3 sp.) 

 Dircenna (8 sp.) 

 Callithomia (3 sp.) 



Mechanitis (17sp.) 

 Ceratinia (23 sp.) Sais (1 sp.) 

 Napeogenes ( 1 7 sp.) Ithomia (107 sp.) 

 Hymenitis (10 sp.) 



Eutresis (1 sp.) 

 Olyras (1 sp.) 

 Melinsea (13 sp.) 



Tithorea (7 sp.) 

 (including Athesis) 



has ventured to withdraw the whole of the genera composing the group Banaoid Heliconidcs, placing them with the 

 DanaidcB, and restricting the family Heliconidce to the two genera Helieonius and Eueides. He has discovered an 

 excellent and constant character for the Banaidce (in which the Da)iaoid Heliconidce participate), in addition to those 

 already known, namely, the existence of a small nervule at the base of the fore-wing median nervure which ana- 



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