WHITEFISHES, LAKE HERRINGS, AND [NCONNU. 493 
THE ROCKY MOUNTAIN WHITEFISH: MALE IN NUPTIAL DRESS. 
An important western representative of these species is the Rocky Moun- 
tain Whitefish or Mountain Herring (Coregonus Williamsonii). It takes 
the hook more readily than its congeners. The males develop peculiar 
tubercles on the scales during the breeding season, which is the late fall or 
early winter. These tubercles are indicated by the white dots in the 
accompanying figure. The females are destitute of them and present the 
ordinary appearance as is shown by the illustration of one of the sub- 
species (Mountain Whitefish) occurring in the Upper Missouri Basin and 
named Coregonus Williamsonii cismontanus, 
MONT Re 
MOUNTAIN WHITEFISH. 
The other species of the genus are Coulter’s Whitefish (Coregonus coul- 
terti) of British Columbia and the Broad Whitefish or Muksun (Coregonus 
Rennicott?) of Alaska. Richardson’s Whitefish (Coregonus richardsonii) is a 
, species of unknown locality and even may not be American. 
The most important of the Lake Herrings or Argyrosomi is the Argyro- 
