498 MR. H. W. BATES ON THE LEPIDOPTERA 



There is a very wide dissimilarity in minor points and in general appearance between 

 the Asiatic set of forms and the American : the only Old World genus which at all 

 approaches the New World group is Samadryas ; but the shape, colours, and neuration 

 of the wings show that it has no close affinity with them. The two sets of forms seem 

 to agree, however, in habits, and apparently occupy the same sphere in the economy of 

 nature in their respective countries. Mr. W^allace, who has had the good fortune to 

 observe both in their native abodes, says, the habits of the South Asian Euploecs (the 

 most numerous genus) are precisely those of the Meliconidce. The Asiatic Danaidce are 

 mostly above the middle size, and include some of the largest Butterflies known ; their 

 American equivalents are in general below the middle size. Both are extremely prolific 

 or abundant in individuals, and are amongst the most characteristic productions of their 

 respective countries. Each set, also, are the objects of numerous mimetic resemblances 

 on the part of other Lepidopterous insects of their own region belonging to different 

 families, — the Asiatic mimickers being modelled after the Asiatic Danaidce, and the 

 American after the American members of the same family. The entire dissimilarity of 

 the two sets of forms would seem to teach us that there can have been no land com- 

 munication east and west between the tropical parts of Asia and America since they first 

 came into existence, and therefore that the great continents must have remained separate 

 in those quarters from a very remote epoch to allow for such an extensive independent 

 development of forms. They are both strictly confined to the hottest parts of their 

 respective hemispheres. In America they are not found beyond the northern tropic, 

 nor much further south than 30° S. lat. They are not known to occur so far from the 

 equator as either tropic in the Old World, but are limited to the south-eastern parts of 

 Asia and the islands of the New Guinea group. The genus Danais, with which we have 

 seen both groups are connected, ranges as far north as 41° in Europe, and 45° in North 

 America. It is interesting thus to find that the only genus wliich is common to the 

 three tropical regions is the sole one of the family that occurs in high latitudes. The 

 only means of communication between the intertropical lands of America and Asia seems 

 to have been a circuitous route by the north (or south) ; and the essentially tropical 

 forms do not appear to have passed along it. The fact of the peculiar equatorial Asiatic 

 Danaidce not reaching Africa is explicable on the same grounds as their entire distinct- 

 ness from the American ones, namely, the non-existence of an equatorial connexion of 

 land of a nature suitable for their transit between the two continents since the remote 

 date when the first forms of the group came into being. 



The habits of the Seliconidce have been described by various travellers, — Lacordaire 

 having given a complete account of the Cayenne species, and Dyson and Gosse some 

 interesting notes on those of Venezuela and Jamaica. The total number of species de- 

 scribed is 284, namely, 233 belonging to the Danaoid, and 51 to the Acrseoid group. They 

 are peculiarly creatures of the forests, and, like the Platyrrhine Monkeys, the arboreal 



stomoses with the median a short distance from its origin. In the systematic part of the present memoir I shall 

 follow Dr. Felder in this altered classification. The two groups which composed the family Heliconidce are, it must be 

 repeated, completely and widely distinct. Yet the analogical resemblance between them is so great, that some species 

 of the one might easily be confounded (if not closely examined) with species of the other. 



