552 THE OCEAN WORLD. 



fishes by the formidable weapon which it carries in its head. This 

 weapon is a prolongation of the muzzle, which, in place of being 

 rounded off or reduced to a point, forms a long, strong, straight 

 sword-like termination, flat on both sides, but on the two edges 

 it is furnished with numerous strong teeth of considerable length, 

 which are prolongations of the hard, bony substance which forms 

 the muzzle forming, in short, a sword-blade deeply toothed on 

 each edge. 



Thus armed, the saw-fish, as it is sometimes called, the length of 

 which is from twelve to fifteen feet, fearlessly attacks the most 

 formidable inhabitants of the sea. With its threatening weapon, 

 sometimes two yards in length, it dares to measure its strength even 

 with the whale. All fishermen who visit the northern seas assert 

 that the meeting of these ocean potentates is always followed by a 

 combat of the most singular kind, in which the activity of the sword- 

 fish is a match for the formidable strength of the whale. Occasionally 

 it dashes itself with such force against the side of a ship, that its 

 sword is broken in the timber. In the British Museum the blade of 

 a sword-fish may be seen which was thus implanted in the timber of 

 a ship. 



IV. GANOIDEA. 



In this order the gills are free and pectinated, as in the ordinary 

 fishes. In the sturgeon the gill-openings present a single, very wide 

 orifice, with an operculum. They are fishes of great size, living in 

 the sea, but ascending the larger rivers in the spawning season. Our 

 space only permits us to notice the Sturgeon, which belongs to the 

 cartilaginous sub-order of the Ganoids ; a second sub- order contains 

 Ganoid fish with bony skeletons, such as the Bony Pike of the United 

 States (Lepidosteus osseus). 



The Sturgeons (Acipenser] are among the largest fishes known. 

 Their muscles, however, are less firmly knit, their flesh more delicate, 

 and their muscular strength is less than one would think from their 

 great size ; their mouths, instead of being armed with so many rows 

 of teeth, are funnel-shaped and protrusible, and adapted for sucking 

 up particles of food ; they are not voracious, and their habits are not 

 at all ferocious. 



The Sturgeons are sea-fishes, periodically ascending and so- 

 journing for a time in the larger rivers of Europe. They abound in 

 the Black Sea and Sea of Azof, but they are chiefly known as 

 frequenting the Volga and the Danube. The enormous consumption 

 of caviare in Russia leads to a deadly pursuit of the common sturgeon 



