CHAMBERS'S INFORMATION FOR THE PEOPLE. 



tody, and this, which is always the upper, is dark 

 in its colour, whilst the opposite side is always 

 white. The two sides of the mouth are not equal, 

 and the pectoral fins rarely so. On the other 

 hand, the dorsal fin, which runs along one of the 

 lateral edges, corresponds with the anal, which 

 occupies the other, and with which the ventrals 

 are sometimes united. They frequent the bottom 

 of the sea, and swim along by an undulating 

 motion of the whole body, while the colour of their 

 upper surface usually corresponds closely with 

 that of the ground on which they lie, and thus 

 they escape the observation of their enemies, 

 and are unnoticed by the small fishes on which 

 they prey. The Flounder, Turbot, Brill, Plaice, 

 Halibut, and Sole are the chief species on our 



Sole (Solea vulgaris). 



own coasts ; they are agreeable and wholesome 

 as food. 



Sub-order (C). The Acanthopteri (Spiny-finned 

 Fishes) in which one or more of the first rays in 

 the fins are supported by a 'spiny,' or injointed 

 bony ray. There is no duct to the swim-bladder. 

 The ventral fins are situated on the breast or 

 throat in the neighbourhood of the pectorals. 

 The scales are generally ctenoid or comb-like. 

 This sub-order includes a great number of families : 



The Labrida (Wrasse or Rock-fish tribe) are 

 known by the thickness and fleshiness of their 

 lips, whence their name. Those of the genus 

 Labrus are called ' old wives ;' and this family con- 

 tains a large number of species, which are prin- 

 cipally inhabitants of tropical seas, and they are 

 of but slight direct importance to man. Some of 

 the tropical forms are remarkable for the beauty 

 of their colours. 



The Fistularidce (Pipe-mouthed Fishes) are 

 recognised by their very prolonged muzzle. They 

 are chiefly found in warm latitudes, but Sea-snipe 

 (Centriscus scolopax] is occasionally found on the 

 Cornish coast as a straggler from the Mediter- 

 ranean. 



The Percidce (Perch tribe) are numerous in the 

 waters of warm climates, some species inhabiting 

 the rivers, and others the sea. Their bodies are 

 oblong, and covered with hard scales ; and the 

 gill-covers are toothed at the margin. The teeth 

 are minute and set together in numerous rows. 

 The ventral fins are generally placed under the 

 pectorals. This family includes the Common 

 Perch (Percaflumatilis}, which is found in almost 

 every piece of clear fresh water, and a large 

 number of marine fishes used as food on different 

 shores. Some of the most remarkable are the 

 Trachznus, or Weaver, which has a very pro- 

 longed and sharp dorsal spine, capable of inflicting 

 a severe injury ; the Pofynemus, or Mango-fish 

 of the Ganges, which has the pectoral fins on each 

 side prolonged into threads thrice as long as the 



168 



body ; the Uranoscopus (Star-gazer), so called 

 from the position of the eyes on the top of the 



Perch (Perca fluviatilis}. 



nearly cubical head ; the Mullus surmulletus 

 (Red Mullet) of British seas, and many others. 



The Triglida (Gurnard tribe) bear a resem- 

 blance to the perches, but have the head armed 

 with spines or hard scaly plates. The Gurnards, 



Gurnard (Trigla pint). 



the Sticklebacks, and the Sebastes, or Norway Had- 

 dock, the spines of which are used by the Green- 

 landers as needles, belong to this family. The most 

 interesting of all is the Dactylopterus, or Flying- 

 fish. This has a kind of supplementary pectoral 

 fin on each side, formed of a membrane stretched 

 over finger-like processes, which in the gurnards 

 are unconnected. By the impulse of these on the 

 surface of the water, the flying-fish can rise several 



Flying-fish (Exocxtus volitans). 



feet into the air, and suspend themselves above 

 the surface for a few seconds, often skimming 

 lightly over it for a considerable distance. 



In the Sparidce (Sea-bream tribe), the genus 



