24 SOUTH-AFEICAN BUTTEEFLIES. 



actually produced no less than 700 species. Mr. Wallace notes 

 (Geogr. Distrib. of Animals, ii. p. 14) that no less than about 200 

 genera, or not far short of half the total number (431) of known 

 genera, are peculiar to the Neotropical Region ; and Mr. Kirby's Cata- 

 logue shows that more than half the entire number of known species 

 have been found within its limits. The Oriental Region, consisting of 

 Tropical Asia and the Indo-Malayan Archipelago, holds the second 

 place, and yields an immense variety of forms, — Mr. Wallace observing 

 that a few months' assiduous collecting in any of the Malay islands 

 will produce from 150 to 250 species, and that thirty or forty species 

 may be obtained any fine day in good localities (^Tropical Nature, &c., 

 p. 74, 1878). Africa, so far as we know at present, is, in comparison 

 with the two regions just mentioned, very poor ; the whole number 

 recorded for the Ethiopian Region (which extends to the Tropic of 

 Cancer northward, and includes Madagascar and various groups of 

 small islands) by Mr. W. F. Kirby -^ being but little over a thousand 

 species. The Australian Region would be less productive than the 

 Ethiopian were the continent of Australia alone to be considered, its 

 poverty in butterflies, except in the north and north-east, being most 

 surprising ; but when with Mr. Wallace we add the very rich Austro- 

 Malayan islands, the number and variety are greatly augmented, — 

 New Guinea, the Moluccas, and Celebes yielding a long series of 

 splendid forms. The Palsearctic Region, notwithstanding its enormous 

 area, lies wholly beyond the Tropic; and although its western half 

 (Europe and the Mediterranean basin) has been incomparably better 

 searched than any other division of the globe, it has not yielded more 

 than about five hundred species." 



The Nearctic or North American Region, in strange contrast to the 

 Neotropical, is no richer than the Palasarctic one, except in the fact 

 that, while the number of known species in the two regions is about 

 the same, the area of the Nearctic is estimated at less than half that 

 of the Palsearctic Region. Generically, all the forms of the former are 

 represented in the latter region. 



Oceanic islands are particularly poor in Rhopalocera, whether lying 

 in tropical or temperate latitudes, and in this respect — as, indeed, in 

 regard to their entire fauna and flora — exhibit (as Darwin, and espe- 

 cially Wallace, have shown) a marked contrast to both recent and 

 ancient " continental " islands, viz., those which have at some time 

 been connected with a continent. All the isolated Atlantic islands, 

 and many of the very numerous Pacific ones, are cases in point, the 

 few butterflies they possess being unmistakably, for the most part, 

 chance settlers from other lands — usually the nearest continent — or 



^ In his most careful and invaluable Synonymic Catalogue of Diurnal Lcpidoptcra 

 (1871), and Supplement (1877). 



2 Dr. Staudinger's very thorough Catalog der LepidoptcrCn des Eur'opcsischen Faunen- 

 gebiets (1871) gives 456 species arranged in 44 genera. 



