The Sffuth Australian Naturalist. 137 



SOUTH AUSTRALIAN FISHES. 



[A new book, "The Pishes of South Australia, ' ' is noticed else- 

 where in this issue, and, by request, the author has kindly 

 supplied the following notes on some of the more interest- 

 ing fishes therein dealt with. — Ed.] 



The sub-title of the book referred to is ''Fishes and Fish- 

 like Vertebrates," thereby implying that not all the forms 

 included are "fishes." The Lancelets and Lampreys form the 

 "fish-like vertebrates"; the first-named are small, slender, 

 worm-like animals, without a skull, the nervous system being 

 developed along the whole of the back, and there is no distinct 

 heart. Certain other forms, comprising the sea squirts, not 

 included in the book, have an incipient backbone (confined to 

 the tail region) in their young stages, but they undergo degra- 

 dation and cannot then be classed as vertebrates, a term imply- 

 ing the presence of a backbone. The Lampreys are higher in 

 the scale than the Lancelets, but fall short of true fishes in 

 having no lower jaw, the teeth in the upper jaw being opposed 

 by a series on the tongue. Sharks and Rays differ from the 

 true or bony fishes in having the skeleton formed of cartilage or 



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Bristly i^og-fish. 



Note the two "fishing rods'' on the snout. Only one specimen has 



been recorded from South Australia. 



gristle, and if the skull is examined it will be found to be 

 composed of small sand-like grains cemented together, and not 

 of interlocking bony fibres, as in fishes proper. There are no 

 true scales, which are a later development, the skin is covered 

 with prickles, so that a sandpaper-like texture is produced; 

 this is known as shagreen. At one time shagreen was used by 



