164 SALMONIDJi:. 



lateral streams of the Jenisej', and in these rivers themselves, also in 

 Lake liaikal and the rivers Angara and Selenga communicating with 

 it, which it ascends at the end of March, before the ice is broken up ; 

 but it is replaced by S. fiuviatiUs towards the autumn. Found also 

 in the Lena and the Witim and in the Kovyma ; in the Witim they 

 are said to grow to the weight of 80 Uis. ; in other rivers the largest 

 scarcely attain to 60 lbs. Many remain in the rivers, which they 

 ascend in early spring to deposit their spawn, and the younger ones 

 especially remain some time, Avhencc they fall into the nets in all 

 seasons, and, with JS.JluviafiJis, Thi/maUiis, and Cyprinus tscJiebaJc, 

 Gohiiis, and Colitis, are almost the sole inhabitants of these rivers. 

 About cataracts and wherever the water is much agitated they are 

 taken with hooks in all seasons. Flesh white, inclining to red, of 

 excellent flavour. Ova small, yellow, like those of the Sturgeon. 

 It is not found in the waters of Kanitschatka, nor in the North 

 Pacific. However, it is said to be found in Japan." 



4. LUCIOTRUTTA. 



Body covered with scales of moderate size. Cleft of the mouth 

 wide ; maxillary long, broad, lanceolate, extending far backwards. 

 Lower jaw much projecting beyond the upper. Dentition very 

 feeble, the teeth being extremely small ; maxillary toothless ; vomer, 

 palatine bones, and tongue with narrow bands of minute, %"illiform 

 teeth. Pyloric appendages in great number. Gill-rakers rigid, 

 awl-shaped, and rough interiorly. 



Migratoiy Trout from Arctic North America ; (? Siberia and 

 Russia). 



1. Luciotrutta mackenzii. 



Inconnu, Mackeiizie, Voy. in N. Ainer. p. 9, and elsewhere. 

 Sakuo mackenzii, Richards. Fi-cmkl. Joiirn. p. 707, pi. 25. f. 1 ; and 

 F(wn. Sor.-Amer. Pise. p. 180, pi. 84. 



B. 10. D. 15. A. 18. V. 12. 



Body rounded, rather elongate ; head long and compressed, with 

 flattened vertex ; eye not very large ; praeoperculum much curved. 

 Dorsal fin nearer to the caudal than to the snout ; caudal forked. 

 Coloration uniform. (Etch.) 



Eiver Mackenzie and its tributaries. Attains to a weight of 15 

 pounds and more. 



2. Luciotrutta (?) leucichthys. 



I suppose that S. leucicJdht/s of -Giildenstadt also belongs to this 

 genus. The distensible mouth, projecting lower jaw, truncated 

 upper jaw, small teeth on the palate, smallish eyes, ten branchi- 

 ostegals, &c. are characters which the Asiatic fish has in common 

 with the Inconnu of the Mackenzie. Giildenstadt and PaUas de- 

 scribe the jaws as toothless, whilst Lepechin expressly mentions 

 these teeth ; perhaps they are deciduous. The figure given by 

 Lepechin is very dissimilar to that of the Inconnu, but these fishes 



