The length of the head is from the point of the snout to the hindmost point or margin of the gill-cover. The length of the body is from the point of the snout to the base of the caudal fin, the fin itself not being included. The depth of the body is from the highest point of the dorsal line to the lowest point of the ventral line, usually from the base of the first dorsal fin to the base of the ventral fin. The expression "head 5" means that the length of the head is contained five times in the length of the body; the expression "depth 5" means that the depth of the body is contained five times in its length; "eye 5" means that the diameter of the eye is contained five times in the length of the head. In describing the fins the spiny rays are denoted by Roman numerals, and the soft rays by Arabic numerals, and the fins themselves by initials; thus "D. 9" means that the dorsal fin is single and composed of nine soft rays; "D. IX, 10" means that the single dorsal fin has nine spiny rays and ten soft rays; when separated by a hyphen, as "D. X-12," it means that there are two dorsal fins, the first composed of ten spiny rays and the second of twelve soft ones; "A. III, 11" means that the anal fin has three spines and eleven soft rays. The expression "scales 7-65-18" indicates that there are seven rows of scales between the dorsal fin and the lateral line, sixty-five scales along the lateral line, and eighteen oblique or horizontal rows between the lateral line and the ventral line. The number of rays in the fins and the number of scales along the lateral line, as given, represent the average number, and are subject to slight variation; thus in some localities the number of rays in a fin may be found to vary one or two, and the number of scales along the lateral line may vary from one to five, more or less, from the number given in the descriptions. I have adhered strictly to the nomenclature of the "Fishes of Middle and North America" (Bulletin, U.S. National Museum, No. 47), by Jordan and Evermann, and in the main I have followed the descriptions as recorded in that admirable work; but in many instances I have depended on my own notes. The suggestions as to angling and the tools and tackle recommended may be confidently relied on, as they are in conformity with my own practice and are based on my personal experience, covering a period of forty years, on many waters, from Canada to the West Indies, and from the Atlantic to the Rocky Mountains. JAMES A. HENSHALL. BOZEMAN, MONTANA. February 1, 1903. SYSTEMATIC ARRANGEMENT OF THE FISHES DESCRIBED IN THIS VOLUME FAMILY =SILURIDÆ= =Ictalurus punctatus= (Rafinesque). =The Channel Catfish=. FAMILY =CYPRINIDÆ= =Cyprinus carpio=, Linnæus. =The German Carp=. FAMILY =ELOPIDÆ= =Elops saurus=, Linnæus. =The Ten-pounder=. FAMILY =ALBULIDÆ= =Albula vulpes= (Linnæus). =The Lady-Fish=. FAMILY =SALMONIDÆ=