percoide^e. 31 



may include one or more fresh-water species *. Even the species cannot be strictly 

 arranged as belonging to salt or fresh-water, several that habitually reside in 

 rivers or lakes occasionally straying to the sea or into tidal waters f ; while of the 

 marine species, some are regularly anadromous, ascending the rivers every season 

 to spawn, others quit the sea occasionally, only, entering the fresh waters in quest 

 of food or shelter at uncertain periods J. Allowing for these cases, then, fourteen 

 of the sixty genera which compose the family may be said to belong to the fresh 

 waters, namely, Aspro and Acerina peculiar to Europe ; Huro, Grystes, Aphro- 

 dederus, Bryttus, Pomotis, and Centrarchus, found in North America §; and 

 Ambassis, Aphrites, and Bides, belonging to the East Indies. Perca has species 

 in Europe, Asia, the Indian Archipelago, North America, and in the West Indies ; 

 Lucio-perca has one representative in Europe, another in Asia, and a third in 

 North America ; and Grystes has one species in the rivers of Carolina and Georgia, 

 and another in the Macquarrie of New Holland, hates may be considered either 

 as a fresh-water or marine genus, one species existing in the rivers of Northern 

 and Tropical Africa, and two others in the sea and rivers of the East Indies ||. 

 It may be gathered from the preceding paragraphs, that in temperate climates the 

 majority of percoidese are found in rivers or lakes, while within the tropics there 

 is a vast preponderance of marine species. 



After the above cursory review of the fresh-water genera, an equally compendious 

 notice of the marine ones, that are common to various districts of the ocean, will 

 enable us to single out the genera or modifications of the percoid form, which have 

 the widest distribution. Serranus (which includes a fourth part of all the species 

 in the family) is much more common within the tropics than elsewhere, but it is 

 known in the Mediterranean, on the Atlantic coasts of Europe, Africa, and of 

 North and South America, in the Red Sea, the Indian Ocean, Polynesia, and sea 

 of Japan, though not on the American side of the Pacific. Labrax, which con- 

 tains only seven species (some of which are littoral or even ascend into fresh waters), 

 is also widely diffused, having representatives in the Mediterranean, on the Euro- 

 pean, and North and South American coasts of the Atlantic, in Polynesia and the 



* Twenty species of Apogon are marine, while A. tkermalis has the very extraordinary residence of warm fresh-water 

 springs. 



f Pena vulgaris has been taken in the Sulway firth, and is reported by PallaB to inhabit the Caspian Sea. Lucio- 

 perca sandra, and the common pike, are also said by the same naturalist to remain in a bay of the Caspian even in the 

 spawning season, without entering the neighbouring rivers, although there is no obstacle to their ascending them. 



% As some species of Labrax, or Basse. Centropomus frequents the mouths of rivers. 



§ Two of the genera are not exclusively North American. Pomotis has a Brazilian species, and Centrarchus a West- 

 Indian one. 



|| Lieutenant Allen found a Lates in the Niger, exactly resembling that of the Nile and Senegal, and Mr. Collie observed 

 a species among the Loo Choo Islands. 



