370 



GEOGRAPHICAL DISTRIBUTION AND 



[Ch. XL. 



observe tliat very few species of marine fisli cross the Atlantic. 

 But a great many species are common to the opposite sides of 

 the Indian Ocean^ inhabiting alike the Red Sea, the eastern 

 coast of Africa, Madagascar, the Manritins, the southern seas 

 of China, the Malay archipelago, the northern coasts of Aus- 

 tralia, and the whole of Polynesia ! ^ This very wide diffu- 

 sion, says Sir J. Richardson, may have been promoted by 

 chains of islands running east and west, which are wantmg 

 in the deep Atlantic. An archipelago extending far in lon- 

 gitude, favours the migration of fish by multiplying the 

 places of deposit for spawn along the shores of islands, and 

 on intervening coral banks ; and in such places, also, fish 

 find their appropriate food. 



Although the marine shells on the opposite side of the 

 Isthmus of Panama are scarcely any one of them the same, 

 yet nearly a third of the marine fishes, or 48 out of 158 

 species, have recently been ascertained by Dr. Giinther to be 

 common to the Pacific Ocean and Caribbean Sea. It has 

 been said in explanation of the species of Testacea being 

 distinct, that the coast on the east side of the isthmus is 

 low, and the sea shallow, whereas the west or Pacific coast 

 is abrupt with perpendicular cliffs. The fish would be 



mor 



r 



coast, and their eggs 

 of the isthmus to the 



mi 



transported from one side 



The flying fish are found (some stragglers excepted) only 



fc) 



from 



approach a higher latitude than the fortieth parallel. The 



course of the 



warmth 



some 



far into the temperate zone ; thus the ch^etodons, whicli 

 abound in the seas of hot climates, are found among the 

 Bermudas on the thirty-second parallel, where they are pre- 

 served in basins inclosed from the sea, as an important ar- 

 ticle of food for the garrison and inhabitants, 

 following the direction of the same great current, range 

 from the coast of Brazil to the banks of Newfoundland. J 



* Eichardson, Brit. Assoc. Reports, .1867, p. 181. 

 1845, p. 190. t Sir J. Richardson, Brit. Assoc, 



t Gardener's Chronicle, Feb. 23, Reports, 1845, p. 190. 



Other fisli, 



( 



I 



th, 



till 



to 



til, 



