164 SALMONID^. 



lateral streams of the Jenisey, and in these rivers themselves, also in 

 Lake Baikal and the rivers Angara and Selenga communicating with 

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

 but il is replaced by 8. jluviatilis 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 lb?, ; 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, whence they fall into the nets in all 

 seasons, and, with S. Jluviatilis, ThymaUus, and Cyprinus tschebaJc, 

 Gobius, and Cohitis, 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 Kamtschatka, 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, vUliform 

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

 awl-shaped, and rough interiorly. 



Migratory Trout from Arctic North Atn erica ; (? Siberia and 

 E-ussia). 



1. Laciotnitta mackenzii. 



Inconnu, Mackenzie, Voy. in N. Amer. p. 9, and eleewhere. 

 Sahno mackenzii, Richards. Frankl. Journ. p. 707, pi. 25. f. 1 ; and 

 Faun, Bor.-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. 

 Dor'sal fin nearer to the caudal than to the snout ; caudal forked. 

 Coloration uniform. (Rich.) 



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

 pounds arid more. 



2. Luciotrutta (?) leucichtliys. 



I suppose that 8. leucichthys of Giildenstadt also belongs to this 

 genus. The distensible mouth, projecting lower jaw, truncated 

 uppfer jaw, small teeth on the palate, smaUish eyes, ten branchi- 

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

 with the Inconnu of the Mackenzie. Giildenstadt and Pallas 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 



