CLASS Y. PISCES: ORDER 3. TELEOSTEA. 



461 



THE HALIBUT. 



species, sometimes measuring seven or eight feet in length, and weighing five or six Imndred 



pounds. It feeds close to the 

 ground on other fiat-fish and va- 

 rious Crustacea. It is abundant 

 in the northern seas on both sides 

 of the Atlantic ; the flesh is firm 

 but dry, and has little flavor; 

 the head and fins are the best 

 parts. This fish is common in 

 the markets of Boston, New 

 York, (fcc. The Greenlanders 

 eat it both fresh and dried ; 



the inhabitants of the Orkneys obtain from it a large quantity of oil. 



THE PIIYSOSTOMATA. 



Wc now come to the last, but still a very extensive division of Teleostea. The term Physo- 

 sto7nuta is compounded of the Greek j^husa, a bladder, and stoma, the mouth, and alludes to an 

 important and distinguishing characteristic, which is, that in all the species the air-bladder is 

 connected with the pharynx by a sort of duct. Most of the group are furnished with a com- 

 plete series of fins, which are always entirely composed of soft rays, with the exception of the 

 first ray in the dorsal, anal, and pectoral fins, which are sometimes spinous. The ventral fins 

 are sometimes wanting; when present, they are always abdominal in position — that is to say, 

 they are situated on the ventral region, behind the pectorals. There is never more than one 

 rayed dorsal fin ; but behind this there is occasionally a second adipose fin. The skin is some- 

 times naked, and sometimes more or less covered with bony plates ; in most cases, however, it is 

 thickly clothed with scales, which always exhibit the cycloid character. The species are exceed- 

 ingly numerous, and inhabit both salt and fresh waters. They include among them some of the 

 most important of the fishes that are sought for by man as food, and also the only species of this 

 order which possess electrical powers. We shall describe them under the following heads: the 

 Clupeidce, Scopclidce, Salmonidw, Galaxiidce, Esncidce, Mormyridce, Cijprinidce, Pceciliidce, 

 Clinracinidce., Siluridce, Loricariid.ee, Amhlyopsida, Murcenidce, Gymnotidce, and Symbranchidce. 

 The three last embrace various kinds of Eels, and are called Apodal or Footless Fishes, as they 

 have no ventral fins ; the others are called Abdominal Fishes, as their ventral fins are placed on 

 the belly behind the pectorals. 



THE CLUPEID^. 



The fishes of this family arc all covered with large thin scales ; the mouth is wide, the dorsal 

 fin large, and there is no adipose fin. It includes some of the most important of all fishes in an 

 economical point of view. 



Genus CLUPEA : Clupea, includes the Herring, C. harengus, abundant in European and 



American waters. It is twelve or thir- 



teen inches long; feeds on various 

 small fishes, including young herrings ; 

 spawns near the first of November ; the 

 fishing-seasonbcgins two or three months 

 earlier, drift-nets being used by the fish- 

 ermen. 



From the statements of several ob- 

 servers, it appears that the Herrings inhabit the European as well as the American seas at all 

 seasons, keeping in deep water during the winter and spring months, and that the appearance of 

 the vast shoals at particular epochs, which has given rise to the idea of their pcrforniing long 

 migrations, is due only to their seeking the shallow waters for the deposition of their spawn. 

 During their migrations for this purpose they swim close to the surface of the water, and so 



THE HERRING. 



