133 



Abt. XXI. — On the Salmonidse of Nev) Zealand. 



By Jambs Hector, M.D., F.K.S. 



(Plates XYIII. figs. 4a and 4b, and XIX.) 



[Read before the Wellington Philosophical Society, June 25, 1870.] 



DuRmo the last few years, Salmon and several varieties of Trout have been 



introduced from England into the Australasian water.s, and the Trout, at least, 



htis been sxiccessfully established, both in this colony and Tasmania. Those 



reared in Nelson, and turned out in the Maitai stream, have already reached 



the full size, so that if they prove as pi'olific as in the native country of the 



species, we may expect soon to have the favoured streams, for a short season 



at least in each year, thrown oi)en to the angler. 



An inquiry, therefore, into the species of fish indigenous to our streams 

 which belong to the same family, some of which might be confounded with the 

 introduced Trout by a casual observer, has a peculiar interest, and though 

 the materials yet obtained are scanty, they are advanced in the hope of 

 inducing further communications on the subject. 



The chief distinguishing character of all fish that belong to the Salmonidoi 

 is the possession of a second dorsal fin, which consists merely of a small fleshy 

 lobe without rays or membrane like the other fins. 



In English Ichthyology the Trouts (including the Salmon of the fish 

 market) form one division of this family, the other division having the smelts, 

 grayling, and fresh- water herrings. 



The representatives of the family in New Zealand belong to the latter 

 miscellaneous group ; the only species hitherto distinguished being referred to 

 a genus {Retropinna) peculiar to these Islands. 



This little fish, which is common in all the sti-eams, was first named by 

 Richardson, Argentina retropinna (Voy. Ereh. and Terr., Ichth., p. 121), but 

 was afterwards separated from this genus and described as Retropinna 

 Ricliardsonii, Gill {Froc. Acad. Nat. Science, Philadelphia, 1852, p. 14). 



Under this name it is described in Dr. Glinther's Catalogue of the Fishes in 

 the Brit. Mus., Vol. vi., p. 171, of which description the following is an 

 absti'act : — 



Genus. Retropinna. 



Cleft of mouth of moderate width. Teeth small, in single series, with a 

 cluster of hooked teeth on the tongue. Dorsal fin set far behind the ventrals, 

 and above the vent. Stomach thick, and of horse-shoe shape. No pyloric 

 appendages or air bladder. Ventral fin 6-rayed. 



Species. Retropinna Richardsonii. 

 Native name, Inanga.* 



Height of body less than length of head, and 4f times its length without 



* Also applied to the young of Galaxias. 



