86 Annals of the Carnegie Museum. 



Scales 7-30-6. The body is compressed less strongly, and is more elongate, 

 than in European examples; ventrals inserted before first ray of dorsal. 



5. Gobio gobio (Linnaeus). 

 Many large specimens not clearly different from the ordinary Gudgeon 

 of Europe, with which the Russian naturalists have identified it. 



6. Leuciscus leuciscus (Linnaeus). 

 Numerous specimens, not different from this common European species. 



7. Rutilus rutilus (Linnseus). 

 Cyprinus lacustris Pallas, Zoog. Ross. -As., Ill, 1811, 314 (all Siberia, Lena River). 



S. 12. W. 4. A. 12. W. 4. V. 10. Scales 8-40 to 44-5 ^ . 



Numerous specimens, corresponding to Rutilus lacustris of Pallas. 

 Most Russian authorities regard lacustris as identical with the Common 

 Roach of Europe, Rutilus rutilus, and we see no reason to question this 

 determination. The American species called Rutilus seem hardly con- 

 generic with it. These should probably stand as Myloleucus Cope. 



Family LUCIID^. 



8. Lucius lucius (Linnaeus). 



Esox reicherti var. baicalensis Dybowski, Verb. Ges. Wien, XXiy, 1874, 391 

 (Lake Baikal). 



Nine specimens from 280 to 440 mm. in length. 



Head 3^ to 2^%\ depth 5>4 to 6; eye 7 to 9 in head. B. 14 or 15. 

 D. 20 or 21. A. 17 to 19. Scales 122 to 137. 



We see no reason to question the identity of this species, "baicalensis," 

 with the Common Pike of Europe, Lucius lucius; nor can we separate 

 the Northern Pike of America, Lucius estor (Le Sueur), from either. In 

 these Siberian examples, the dark bar under the eye is a shade more distinct 

 than usual, and the pale spots on the sides show a greater tendency to 

 array themselves in pale cross-bands, especially on the tail. The anal 

 rays are 17 in 4 specimens, 18 in 3, and 19 in 2. 



In the description of Esox baicalensis the vertical fins are described 

 as unspotted, which is not the case in our examples, nor in any other 

 specimens of Lucius lucius. The lesser diameter of the eye is said to be 

 10 to 15 times in the head in a specimen a meter in length. 



Lucius reicherti of the Amur River is said to be spotted with dark. 

 It is probably therefore a species of the Maskinonge group, to which the 

 subgeneric name of Mascalongus has been applied. 



