415 



Gulf-stream, and African currents, the modification of the zones 

 of temperature in the Atlantic is very striking — for instance, the 

 temperate zone on the American side extends only from Cape 

 Hatteras to Cape Cod, about ten degrees of latitude, while on tlie 

 Eux'opean it extends from the coast of Sweden to the Cape de Vei*d 

 Islands, nearly five times as many degrees — on the contrary, the 

 tropical zone, which extends in America from Cape Hatteras to 

 25° S. latitude, or sixty degrees, extends only about twenty de- 

 grees on the African Guinea coast. The line of temperature 

 established by the average of the thirty coldest days in the year, 

 gives the clue to the distribution of the marine fauna ; in America 

 this is essentially tropical, and in Europe essentially temperate. 



Of the families mentioned in this list, the Cottoids are essen- 

 tially North American, and ther eare five in Jamaica ; the Scice- 

 noids are tropical, Europe having but a few ; the Sparoids are 

 essentially Mediterranean, where fifteen genera exist, and there 

 are four in Jamaica ; the Squammipennce are tropical, and numer- 

 ous in Jamaica ; the Scomberoids are cosmopolitan, and numerous 

 everywhere ; the Mullets are tropical, and there are several in 

 Jamaica ; the Lahroids, very rare here, are numerous in the tro- 

 pics ; the Gyprinoids, though quite cosmopolitan, have never been 

 found in South America, and there are none in Jamaica ; one 

 Gentropomus is found in fresh water in Jamaica, which is unusual ; 

 the Siluroids are few, those of America are few in comparison 

 with those of Asia ; while a kindred family, the Goniodonts, are 

 peculiar to this country ; the Pleuronectidce belong to the tem- 

 perate zone, yet there are few here. 



J. M. Barnard, Esq., stated a fact in confirmation of the tropi- 

 cal character of the American marine fauna ; he had lately 

 received a keg of echinoderms from Zanzibar, in 5° S. latitude, 

 which were almost identical with those from East Florida. 



Prof. Parsons stated some facts in regard to the ani- 

 mals of the White Mountains, which he had learned 

 from an experienced hunter, especially in respect to the 

 abundance of the sable and deer. 



Prof. Agassiz remarked that the fauna of the Adiron- 

 dac Mountains, 1500 feet above the sea, is essentially 

 that of the fur countries. 



