THE SALMON FAMILY. 47 
The writer and his associate, Professor Charles H. 
Gilbert, have had, under the auspices of the United 
States Fish Commission, better opportunities to 
study the different species of Oncorhynchus than 
have fallen to the lot of any other ichthyologists. 
The following discussion of the different species 
is condensed from our report to the United States 
Census Bureau, portions of which were published 
in the ‘“ American Naturalist” for March, 1881. En- 
tirely similar conclusions have been independently 
reached by Dr. Tarleton H. Bean, who visited Alaska 
in 1880, and whose means of studying the species 
have been scarcely less extensive. 
There are five species of salmon (Oxcorhynchus) 
in the waters of the North Pacific. We have at 
present no evidence of the existence of any more 
on either the American or the Asiatic side. These 
species may be called: (1) the Quinnat, or King 
Salmon, (2) the Blue-back Salmon, or Red-fish, 
(3) the Silver Salmon, (4) the Dog Salmon, and 
(5) the Humpback Salmon; or (1) Oxcorhynchus 
tschawytscha, (2) Oncorhynchus nerka, (3) Oncorhyn- 
chus kisutch, (4) Oncorhynchus keta, and (5) Oxco- 
rhynchus gorbuscha. All these species are now 
known to occur in the waters of Kamtschatka as 
well as in those of Alaska and Oregon. These 
species, in all their varied conditions, may usually 
be distinguished by the characters given below. 
Other differences of form, color, and appearance 
are absolutely valueless for distinction, unless 
specimens of the same age, sex, and condition 
are compared. 
The Quinnat Salmon (Oxcorhynchus tschawytscha) 
