While the last-mentioned families contain only fishes of truly pelagic habits, the next (_Sparidæ_), formed by the Sea Breams, generally keep near the coast, and often enter fresh waters. In these the body is much compressed laterally, and is covered with large scales; the first half of the dorsal fin is also spinous. The Common Sea Bream (_Sparus auratus_), characterised by its red colour with brilliant golden reflections, and by a dark spot on the shoulder, may often be angled from rocks and piers. The young, in which the dark spots have not yet appeared, are known as Chads, and are often regarded as a distinct species. The Black Bream (_Cantharus lineatus_) is an omnivorous feeder, and will take both animal and vegetable baits. The Red Mullets (family _Mullidæ_) may be distinguished from the grey mullets previously described by the two long erectile barbules on the lower jaw. The scales are large and thin, with serrated edges, and the front portion of the dorsal fin has weak spines. The common British species (_Mullus barbatus_) frequents our south and east coasts, being specially abundant round Devon and Cornwall, where they often occur in vast shoals, and the young are often to be caught in estuaries and harbours. Our last example is the Common Bass or Sea Perch (_Morone abrax_), of the family _Serranidæ_. It is also known locally as the White Salmon and the Salmon Dace. This fish may be taken with rod and line on rocky coasts and at the mouths of rivers. The sand-eel, or an artificial imitation of it, is commonly used as bait, but the Cornish fishermen more frequently employ a piece of herring or pilchard for the purpose. The first dorsal fin of this fish has very strong spines which may inflict severe wounds when the live creature is carelessly handled. * * * * * Omitting all mention of sea birds, for the reason previously given, we now pass to the highest division of vertebrates--the Mammals--of which we shall describe but one species--the Common Porpoise, this being the only marine mammal that can be regarded as a frequent visitor to the British coasts in general. It may be well at the outset to understand exactly why the porpoise is classed with the mammals and not with the fishes--to see how its structure and functions correspond with those of our own bodies rather than with those of the animals dealt with in the preceding portion of the present chapter.