204 The Scyphophori, Haplomi, and Xenomi 



some extinct genus which, unlike Chologaster , retains these 

 fins. The translucent body, as in the other blindfishes, is 

 covered with very delicate tactile papillae, which form a very 

 delicate organ of touch. 



The anomalous position of the vent in Amblyopsida occurs 

 again in an equally singular fish, Aphredoderus sayanus, which 

 is found in the same waters throughout the same region in 

 which Chologaster occurs. It would seem as if these lowland 

 fishes of the southern swamps were remains of a once much 

 more extensive fauna. 



No fossil allies of Chologaster are known. 



Kneriidse, etc. The members of the order of Haplomi, recorded 

 above, differ widely among themselves in various details of 

 osteology. There are other families, probably belonging here, 

 which are still more aberrant. Among these are the Kneriida, 

 and perhaps the entire series of forms called Iniomi, most of 

 which possess the osteological traits of the Haplomi. 



The family of Kneriid includes a few very small fishes of 

 the rivers of Africa. 



The Galaxiidae. The Galaxiidce are trout-like fishes of the 

 southern rivers, where they take the place of the trout of the 

 northern zones. The species lack the adipose fins and have 

 the dorsal inserted well backward. According to Boulenger 

 these fishes, having no mesocoraoid, should be placed among 

 the Haplomi. Yet their relation to the Haplochitonidce is very 

 close and both families may really belong to the Isospondyli. 

 Galaxias truttaceus is the kokopu, or "trout," of New Zealand. 

 Galaxias ocellatus is the yarra trout of Australia. Several other 

 species are found in southern Australia, Tasmania, Patagonia, 

 and the Falkland Islands, and even in South Africa. This very 

 wide distribution in the rivers remote from each other has given 

 rise to the suggestion of a former land connection between 

 Australia and Patagonia. Other similar facts have led some 

 geologists to believe in the existence of a former great con- 

 tinent called Antarctica, now submerged except that part which 

 constitutes the present unknown land of the Antarctic. 



As intimated on p. 253, Vol. I, this distribution of Galaxias 

 with similar anomalies in other groups could not if unsupported 

 by geological evidence be held to prove the former extension 



