FISH IN GENERAL. 41 



a chain of soundings is said to exist from continent to conti- 

 nent, near the equator. 



Although the number of species clearly proved to visit both 

 continents be not considerable, and fewer reach the Indian 

 Ocean, still along with the floating weed species of serranus, 

 rypticus, polyprion, trichiurus, belone, hemiramphus, &c. are 

 common to the soundings of America, as well as Africa and 

 Eui'ope ; and tribes of caranx, seriolus, scomber esox, and 

 sphyrama, are seen not alone about these plants, but in still 

 greater numbers in the track of the medusae, where they as 

 well as the troops of pelamis, thynnus, and temnodon, are 

 accused of acquiring the noxious property which poisons the 

 unwary seaman, and is known by the name of ichthic venom. 



Towards the polar circles, but more particularly in the 

 temperate latitudes of both hemispheres, there are periodical 

 extensions of residence among the coasting species, regulated 

 by the progress of the sun towards either side of the tropics. 

 It is particularly observable where a great current sets from 

 a warm towards a cold latitude ; as in the gulf stream of 

 Florida, whose tepid waters only partially depositing their 

 alluvials on the Bahamas, rush onward, till they are checked 

 by the counter current of the St. Lawrence, and the icy influx 

 from the pole, and form the sandy precipitation of the banks 

 of Newfoundland. The tropical fish carried along in this 

 current without sensible diminution of temperature, divide 

 nevertheless at the first mentioned deposit, where the coast- 

 ing species and those which frequent soundings remain, while 

 the truly pelagic, thynnus, caranx, temnodon, the squali, and 

 even exocetus, proceed to the second, where they are met by 

 the polar colonies of gadi and resident pleuronectes \ Thus 



1 I have witnessed the taking of a flying fish on the 23d September, 

 1816, on the same day that we passed two icebergs, at no great distance 

 from the island of Sable, near Halifax, The summer progress of the 



