3. BRA.CHTMASTAX. 



163 



This genus is intermediate between Salmo and Coregonus. Even 

 ]i Salmo fiuviatiUs (p, 141) should prove to be the male of Salmo 

 corecjonoides, still the small size" of the ova would be a character of 

 sufficient importance to separate these fishes generically from Sahno. 



1. Brachyaystax coregonoides. 



Salmo lenok, Pallas, Heise, ii. Append, p. 716; L. Gm. iii. p. 1373. 



coregonoides, Pallas, Zoogr. Ross.-As. iii. p. 362 ; Cui). 8f Vol. 



xxi. p. 272. 



B. 11-12. D. 14. A. 12-13. L. lat. 144-164. 



Habit stout ; head of moderate size, its length being two -ninths 

 of the total (without caudal) ; bones of the head very solid. Snout 

 of moderate extent, broad, obtuse ; teeth small ; vomer with teeth 

 anteriorly only. Maxillary similar to that of a Coregonus, short 

 and broad, not extending, to below the middle of the eye. Pra3- 

 operculum with a long lower limb. Adipose fin large and thick; 

 caudal deeply emarginate. Body with numerous brown spots. 



We refer two specimens from Pallas's Collection to this species : 

 one (no. 86) is 18 inches long, and evidently the typical specimen ; 

 the other (no. 84) is 21 inches long, and, although named " O.flu- 

 viatilis var. taimen,^' is most certainly another individual of the same 

 species. 



" It abounds in rivers and the strong mountain-tornents of the 

 Altai, which are tributaries of the Ob and Irtis, as also in the cd- 



