16 FISHES OF AUSTRALIA. 



Brown Groper (Achcerodus ba-dins). 



White-spotted Parrot-Fish (Pseudolabrns gymnogenis). 



Rainbow-Fish (Coris lineolata). 



Herring-Kale (Olisthops cyanomelas). 



Yellowtail (Trachurus declivis). 



Trevally (Caranx georgianus). 



Flathead (Platycephalus fuscus). 



Red Gurnard (Chelidomchthys kumu). 



In addition to the above-mentioned species, there can 

 be little doubt that most of our marine fishes produce 

 pelagic eggs. 



Demersal eggs are characterised by their usually larger 

 size and greater weight; the latter causing them to sink 

 after extrusion from the body of the parent. They also 

 show a tendency to be more-or-less opaque. Many 

 demersal eggs are adhesive ; readily adhering to one 

 another or to foreign objects such as sticks, stones, 

 weeds, etc. Demersal adhesive eggs are produced by the 

 Garfishes, the Hardyheads, the Murray Cod and probably 

 by most of our fresh-water fishes. Those of the common 

 Catfishes and of the various kinds of Trout, may be taken 

 as types of demersal eggs which are not of an adhesive 

 nature. 



Generally speaking, those fishes which reproduce by 

 means of pelagic eggs, produce an infinitely greater quan- 

 tity, than do those whose eggs are of a demersal char- 

 acter ; and well is it that this is so, as the chance of sur- 

 vival is usually very much less in the case of eggs thrown 

 broadcast on the surface of the ocean, than it is in those 

 which are attached to some object, and which may even 

 be watched over to some extent by the parents. 



Of viviparous Teleostean fishes, the small Crested 

 Weed-Fishes of the genus Cristiceps may be mentioned 

 as Australian examples. 



As I before stated, the Sharks and Rays are principally 

 viviparous, the exceptions, in Australian waters, being the 

 True Skates (Raia), the Dog-Fishes or Cat-Sharks, and 

 the Port Jackson Sharks. In these the eggs, which are 

 exceedingly large, are encased in a horny covering and 



