J4 FISH AND FISH-LIKE ANIMALS OF N.S.W.j 



Part ii. 



Fishes.— CLASS PISCES. 



BONY PISHES— Subclass TELEOSTEI. 



The major divisions or Orders of the Fishes are each distinguished by com- 

 plicated combinations of several external and internal characters; any of these 

 uiay vary within the limits of a division, and may approach or even overlap those 

 of some other division. There can accordingly be no simple key by which the 

 Orders may be distinguished, but the characteristic features of each are stated 

 under their propei headings, as follows : — 



Herrings and Trout-like Fishes— Order ISOSPONDYLI. 

 Only one true dorsal fin, which is without spines; a secondary adipose dorsal 

 may be present or absent. 



A. One dorsal fin, no secondary adipose fin posteriorly. 

 B. Body scaly. 



C. 9-16 rays in the ventral fins. 



D. An elongate bony plate on the throat between the two branches of 



the lower jaw. Fam. Elopidae (No. xxvi.) . 



DD. No such bony plate. Fam. Albulidac (No. xxvii.). 



CC. Not more than 8 rays in the ventral fin. 



E. No lateral line. 



F. Dorsal fin posterior, opposite the anal. 



Fam. Chiroccntridae (No. xxviii.) . 

 FF. Dorsal fin median, well before the anal. 



G. Maxilla very large, greatly produced backward. 



Fam. Engraulidae (No. xxix.). 

 GG. Maxilla small or of moderate size, not produced unusuallv 

 far backward. Fam. Clupeidae (No. xxx.) . 



EE. Lateral line present. 

 H- Mouth terminal, no rostral barbie, tail forked. 



Fam. Chanidae (No. xxxi.). 

 HH. Mouth overhung by the snout, a rostral barbie, tail 



emarginate. Fam. Gonorhynchidae (No. xxxiij. 



BB. Body naked. Fam. Galaxiidae (No. xxxiii.). 



