ZOOLOGY. 



the ventral fins attached to the abdomen behind 

 the pectorals. It includes the greater number of 

 the fresh-water fishes. There are five families. 



The Cyprinidce (Carp tribe) are all fresh-water 

 fishes. The mouth is shallow, the jaws feeble, 

 and the pharynx strongly toothed. They feed 

 chiefly on seeds and decomposing vegetable 

 matter. One of the finest European species is 

 the Carp (Cyprinus carpio), which is imported 

 into England, and thrives well in ponds and lakes. 

 The Barbel and the Cobitis or Loche are allied 

 species well known to anglers. The Gold-fish 

 of China (C. auratus), now naturalised in this 

 country, also belong to this family. The Anableps, 

 from the rivers of Guiana, has the cornea and iris 

 divided by transverse bands, so as to give the fish 

 the appearance of having four eyes. 



The Esocida (Pike tribe), the most voracious of 

 the fresh-water fishes, are characterised by the 

 absence of fatty matter in the dorsal fin, and by 

 the position of this opposite to the anal. fin. The 

 Pike (Esox Indus) sometimes weighs forty pounds, 

 and is very destructive to the smaller fishes in the 

 ponds and rivers which it inhabits. The Gar- 

 fish, or Sea-pike, which frequents the British 





this operation is accomplished, they return to the 

 sea, followed by the young fish. The best known 

 British species are the Common Salmon (S. salar\ 



Pike, or Jack (Esox lucius). 



shores, sometimes attains the length of eight feet. 

 The Mackerel-pike, or Saury, a British species, 

 is gregarious in its habits, and is preyed upon by 

 porpoises and tunnies. 



The Silurida (Sheat-fishes) have no true scales, 

 the skin being either naked or covered with bony 

 plates. They inhabit the rivers of warm climates. 

 The genus Silurus have a strong spine in front of 

 the dorsal fin, which can be laid flat or raised 

 perpendicularly, so as to form a formidable 

 weapon. The Malapterurus electricus of the 

 Nile and rivers of Central Africa, which attains 

 the length of twelve inches, has electric properties 

 similar to those of the torpedo and gymnotus. 



The SalmonidcE (Salmons and Trouts) are very 

 extensively, indeed almost universally, diffused over 

 the globe ; some of them being confined to fresh ! 

 water, and others passing a part of their lives in j 

 the sea, but resorting to rivers to deposit their ; 

 eggs. They are distinguished by the fatty deposi- , 

 tion in the dorsal fin. All of this family are \ 

 clouded with dusky patches when young, and 

 many remain permanently spotted. The flesh of 

 most of them is esteemed as food. The Salmon 

 inhabits the seas of comparatively cold regions, 

 ascending the rivers for the purpose of spawning, 

 at seasons varying with the climate. They swim 

 against powerful streams, and leap up cascades of 

 considerable elevation, and find their way to the 

 brooks and small lakes of lofty mountains. After 



Salmon (Salmo salar). 



the Salmon Trout (S. truttd), and the Gray or 

 Bull Trout (S. eriox). The Trout appears to vary- 

 much in size and colour according to the climate 

 and other conditions of its residence, so that it is 

 difficult to distinguish species from mere varieties. 

 The Common Trout (Salmo fario], whose growth 

 is wonderfully rapid, is too well known to require 

 description. The Smelt (Osmerus) and Grayling 

 (Thymallus) of British rivers, and the Capelin, 

 which is used on the shores of Newfoundland 

 for bait, also belong to this family. 



The Clupeidce (Herring tribe) is one of the most 

 important families in the whole class, for the 

 amount of food it supplies to man. The fishes 

 belonging to it resemble the Salmonidae in many 

 characters, but differ in having no fatty matter in 

 the dorsal fin. They chiefly inhabit the seas of the 

 temperate zone. The Herring (Clupea harengus) 

 usually lives in open ocean, but periodically visits 

 the nearest coast in immense shoals to deposit its 

 spawn. There are many species, differing but little 

 from the herring. Thus, the Pilchard is caught on 

 the Cornwall coast, the Sardine on the west coast 

 of France and in the Mediterranean, where the 

 Anchovy, well known for its rich and peculiar 

 flavour, also abounds. The Sprat, Whitebait, and 

 Shad belong to the same family. 



Sub-order (B). The Anacanthini have the fins 

 entirely 'soft.' The ventral fins, if present, are 

 brought forward beneath, or even in advance of 

 the pectorals. If the swim-bladder is present, it 

 never communicates with the gullet by a duct. 

 Two groups are included under this sub-order : 



1st Group, the Apoda, which are destitute of 

 ventral fins. The Sand-eels (Ammodytes) belong 

 to this group. They bury themselves in the sand 

 during the ebb of the tide, and are used as bait by 

 the fishermen. 



In the id Group, the Sub-branchiata, the ventral 

 fins are present. It comprises two families 



Family Gadidcs (the Cod tribe) are easily known 

 by the softness of all their fins, and by having the 

 ventrals inserted under the throat, and pointed. 

 To this family belong the Haddock, Whiting, 

 Ling, Pollack, and the Cod itself. Besides being 

 used as food, the oil obtained from their livers is 

 very serviceable in the arts and in medicine. 



The second family is that of Pleuronectida 

 (the Flat-fish or Flounder tribe). The body 

 is compressed from side to side, and margined 

 almost throughout by long dorsal and anal fins. 

 The two flat surfaces one of which, in the ordin- 

 ary position of the fish during life, is above, and 

 the other below are in reality the two sides of 

 the fish, differing in several important respects. 

 The bones of the head are singularly twisted, so 

 that both the eyes are placed on one side of the 



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