_Esox lucius._ The Pike. Body elongate; head 3-1/3; depth 5; eye 6; B. 14 to 16; D. 16 or 17; A. 13 or 14; scales 125; cheeks entirely covered with scales; lower half of opercles naked, upper half with scales. _Esox reticulatus._ Eastern Pickerel. Body elongate; head 3-1/2; depth 6; eye 8; B. 14 to 16; D. 14; A. 13; scales 125; cheeks and opercles entirely covered with scales. _Esox vermiculatus._ The Western Pickerel. Body elongate; head 3-1/4; depth 5 to 6; eye 6; B. 12; D. 11 or 12; A. 11 or 12; scales 105 along the lateral line; cheeks and opercles entirely covered with scales. _Esox americanus._ The Banded Pickerel. Body elongate; head 3-1/2; depth 5-1/2; eye 5; B. 12 or 13; D. 11 or 12; A. 11 or 12; scales 105; cheeks and opercles entirely covered with scales. As some anglers find it difficult to distinguish a large pike from a mascalonge, or a pike from a pickerel, owing to the similar shape and appearance, the several species can be easily identified by means of the following artificial key: The mascalonge (_Esox nobilior_) has the upper part of both the cheeks and gill-covers scaly, while the lower half of both cheeks and gill-covers is naked; it has from 17 to 19 branchiostegal rays (the branchiostegals are the rays on the under side of the gill-cover, that, like the ribs of an umbrella, assist in opening and closing it during breathing). Its coloration is of a uniform grayish hue, or when marked with spots or bars they are always of a much darker color or shade than the ground color. The pike (_Esox lucius_) has the cheeks entirely scaly, but only the upper part of the gill-cover, the lower half being naked; it has from 14 to 16 branchiostegal rays; its coloration is a bluish or greenish gray, with elongated or bean-shaped spots covering the sides, and which are always of a lighter hue than the ground color. The eastern or reticulated pickerel (_Esox reticulatus_) has both the cheeks and the gill-covers entirely covered with scales; it has from 14 to 16 branchiostegal rays; its coloration is shades of green, with sides of golden lustre, and marked with dark reticulations, mostly horizontal. It is rarely or never found west of the Alleghanies. The little western pickerel (_Esox vermiculatus_) has both cheeks and gill-covers entirely scaly, as have all the pickerels; it has from 11 to 13, usually 12, branchiostegal rays; its coloration is greenish or grayish, with curved streaks on the sides forming bars or reticulations; the color is quite variable, sometimes plain olive. It is found only west of the Alleghanies.