A red fish; this is very rich in fat, which is found most abundantly on the under side. Its flesh is so rich that most people require a corrective in the way of vinegar or other acid sauce. In selecting salmon, one with a small head and tail and broad shoulders is best. The scales should be bright and silvery. The more freshly a salmon is cooked the better.

Eel is exceptionally rich in fat, the proportion being about double that of proteins. Although oily, it is readily digestible and possesses a delicate flavour. There are salt- and freshwater eels. The conger eel is a favourite with many people. The flesh is firm and hard, and requires long and careful cooking.

Herring is the cheapest and most abundant of the oily fishes. West coast fishes are the richest and largest; those caught off the East coast are smaller, seem less fat, and are not so indigestible. This fish should be cooked fresh; when newly caught they have a bright and silvery appearance. If red about the eyes they have been dead some time. It should be well covered with scales, and plump. Herring are much used in the salted and smoked forms. When smoked for an hour or two they are called "bloaters." As the smoking continues, they become "kippers," "red herring," or "black herring".

Mackerel readily taints, and gives rise to symptoms of ptomaine poisoning if eaten in this condition. The mackerel seasons are spring and autumn; the latter fish are the finer. Sardines, sprats, and pilchards belong also to this group of fish.

The Crustacea require a few words; the edible forms are lobster, crab, crayfish, shrimps, and prawns.

The lobster and crab consist of two distinct parts. The flesh, which is contained in the claws, legs, and tail, is very indigestible, mainly on account of the density and coarseness of the fibres. The habit of eating vinegar with lobster and crab is perfectly sound, the acid helping to soften the fibre. The body of these animals is also eaten. This is composed mainly of liver; it contains a considerable quantity of fat, and is very rich.