306 Dr. A. Giinther on a new form of Mudfish. 



three species are known ; and, finally, a minute form is said to 

 occur in Chile. The occui'rence of the same natural genus of 

 freshwater fishes in Australia, New Zealand, and South America 

 would appear to be significant enough, and must be the more 

 so when we find that even one and the same species {Galnxias 

 attenuatus) inhabits the fresh waters of countries separated at 

 present by the South Pacific Ocean. Nor does this fact stand 

 alone, inasmuch as another family of freshwater fishes, that of 

 Haplochitonida, offers a very similar instance of geographical 

 distribution — one of the two genera of which it is composed 

 being found in Terra del Fuego and the Falkland Islands {Hap- 

 lochiton), the other in Southern Australia [Prototroctes) . These 

 instances seem to be confirmatory of an observation made in 

 Proc. Zool. Soc. 1858, p. 390, where the Batrachian fauna of 

 South America was shown to be most closely allied to that of 

 Australia. 



By the last New Zealand mail I received a highly interesting 

 example belonging to this family of Galaxidse, differing generi- 

 cally, however, from Galaxias in being devoid of ventral fins. 

 It is the type of a new genus, which may be characterized 

 thus : — 



Neochanna. 



General characters those of Galaxias. Ventral fins none. 

 Each jaw with a single series of very small, compressed (incisor- 

 like) teeth of equal size; palate toothless. A series of hook-like 

 teeth on each side of the tongue. Pyloric appendage single. 

 Gill-rakers very short, conical, widely set. 



Neochanna apoda. PI. VII. 

 B. 7. D. 16. A. 17. 



Body subcylindrical, compressed behind, rather elongate, its 

 depth being contained seven times and a half in the total length 

 (without caudal). Head broad and depressed, its greatest width 

 being much more than its depth, and at least two-thirds of its 

 length, which is a little less than one-fifth of the total (without 

 caudal). Snout broad, obtusely rounded. Lips broad. Cleft 

 of the mouth of moderate width, the maxillary extending to 

 below the eye, which is very small. Anterior nostril prolonged 

 into a minute tube ; several wide pores on the upper part of 

 the head. A rather deep groove runs from the head along 

 the middle of the back and abdomen. The dorsal and anal 

 fins are about as high as the tail between them, and both are 

 continuous at the base with the rudimentary rays of the caudal 



