[Illustration: Fig. 152.--Serranus altivelis.] The “Sea perches proper” are found on the shores of all temperate and tropical seas, most abundantly in the latter. A few species enter brackish and even fresh water, one having been found as high up the Ganges as the confines of Nepal. However, all spawn in the sea. The variety of species is almost infinite, about 150 being tolerably well known, and many more having been described. The distinction of the species is most difficult, and nearly impossible to those who have no opportunity of closely and long observing them in nature, as they are not only subject to great variation of colour, but also to considerable changes dependent on age. Many are most agreeably coloured, and ornamented with spots, or cross bands or longitudinal stripes; colours which become more uniform with age in those species which attain to a large size. The majority remain of rather small size, growing to a length of one or two feet; but not a few reach more than twice that length, and may even become dangerous to man. Instances of bathers having been attacked by a gigantic species not uncommon at the Seychelles and Aden are on record, the persons having died from the injuries received. Almost all the species are eatable, and many are esteemed as food. One species is common on the British coasts (_S. cabrilla_), and probably some of the more southern species (_S. scriba_ and _S. gigas_) occasionally wander as far northwards as the British Channel. The species figured, _S. altvelis_, is locally distributed over nearly all the tropical parts of the Indian Ocean, and distinguished by particularly high dorsal and anal fins. _Anyperodon_ and _Prionodes_ are two genera closely allied to _Serranus_. PLECTROPOMA.--Form of the body and dentition (see p. 127, Fig. 54) similar to that of _Serranus_, with a præoperculum serrated behind, and armed with spinous teeth below, which are directed forwards. Dorsal fin with from seven to thirteen spines. About thirty species from tropical seas are known. _Trachypoma_ is allied to this genus. POLYPRION.--Body oblong, rather compressed, covered with small scales. All the teeth are villiform; teeth on the vomer, palatine bones, and the tongue. One dorsal with eleven or twelve spines; anal with three. Præoperculum denticulated; a strong, rough, longitudinal ridge on the operculum. Two species are known: one from the European coasts (_P. cernium_), and one from Juan Fernandez (_P. kneri_). They attain to a weight of 80 lbs. and more. The European species has the habit of accompanying floating wood, to which they are attracted by the small marine species generally surrounding such objects, and affording a supply of food. It is known by the name of “Stone-bass,” and excellent eating.