Bull. U. S. F. C. 1891. Fish-cultural Investigations in Montana and Wyoming. (To face page 60 18.) 
Plate XXIII. 
m iSTSsiai iiii 
V-' 
P . ' ^ ,:M 
■ .. .m 
1 . Salmo IRIDEUS Ayres. Rainbow Trout. Adult male. Three-tenths natural size. 
2. Salmo IRIDEUS. Rainbow Trout. Young. Five-eighths natural size. 
3. SALMO FARIO Will. Von BehrTrout. One-haif uatural size. 
