210 FISHES. 



2. Lates calcarifer is common in India as well as in 

 Queensland. 



3. Galaxias attenuatus inhabits Tasmania, New Zealand, 

 the Falkland Islands, and the southernmost part of the South 

 American continent. 



4. Several Petromyzonts enter the fresh waters of Tas- 

 mania, Sovith Australia, New Zealand, and Cliili. 



B. Genera identical in distant continents — 



1. The genus Umbra, so pecuHar a form as to be the type 

 of a distinct family consisting of two most closely allied 

 species only, one of which is found in the Atlantic States 

 of North America, the other in the system of the Danube. 



2. A very distinct genus of Sturgeons, Scaphirhynchus, 

 consisting of two species only, one inhabiting fresh waters 

 of Central Asia, the other the system of the Mississipf)i. 



3. A second most peculiar genus of Sturgeons, Polyodon, 

 consists likewise of two species only, one inhabiting the 

 Mississippi, the other the Yang-tse-kiang. 



4. Amiurus, a Siluroid, and Catostomus, a Cyprinoid genus, 

 both well represented in North America, occur in a single 

 species in temperate Cliina. 



5. Lepidosiren is represented by one species in tropical 

 America, and by the second in tropical Africa {Protopterus). 



6. Notopterus consists of three Indian and two West African 

 species. 



7. Mastacemhelus and Ophiocephalus, genera characteristic 

 of the Indian region, emerge severally by a single species in 

 West and Central Africa. 



8. Symbranclms has two Indian and one South American 

 species. 



9. Prototroctes, the singular antarctic analogue of Core- 

 gonus, consists of two species, one in the south of Australia 

 the other in New Zealand. 



