54 PIPE-FISH; HIPPOCAMPUS. PLECTOGNATHI. 



species, and at the base of the tail in others. In this pouch the 

 eggs become matured ; and when the fry are ready to escape, it 

 opens and allows them to pass out. This contrivance reminds 

 us of the pouch of the Marsupial Mammalia ; but there is this 

 striking difference, that in the latter it is the Female which affords 

 this protection to the young, whilst in the Pipe-fishes it -is the 

 Male. It has been asserted that, even after the young have 

 quitted the pouch, they will return to it again ; and that the 

 parent shows great attachment to them. The Hippocampus 

 (Fig. 259) has a prehensile tail, unfurnished with any finny 

 expansion ; and is enabled by its means to climb or hold on by 

 the stalks of marine plants. It is only in the dead specimen, 

 that the neck acquires the peculiar bend, which gives its head the 

 resemblance to that of a Horse, from which its name is derived. 

 The Pegasus, though furnished with a snout, has the mouth 

 beneath it ; the pectoral fins are large, and are spread out in a 

 wing-like manner; whence these curious Fishes have derived 

 their name, which signifies Flying Horses. 



ORDER VI. PLECTOGNATHI. 



579. We next come to another small order, which forms a 

 connecting link between the Osseous and Cartilaginous fishes. It 

 resembles the latter, in having the upper jaw attached to the 

 cranium, in such a manner as to possess but little power of 

 motion (whence is derived the name of the Order, which means 

 having the jaws soldered), and also in the imperfect ossification 

 of the skeleton. Still, in its general conformation, the skeleton 

 rather resembles that of the bony fishes. The gill-lid is con- 

 cealed under the thick skin, as in the preceding Orders ; and 

 there is but a small gill-opening on either side : the ribs are 

 scarcely developed. This Order includes two families, which are 

 distinguished by the structure of their teeth. In the first of 

 these, the Gymnodontes, or Fishes with naked teeth, the jaws are 

 shaped like the beak of a Parrot ; and are composed of parallel 

 plates of a substance resembling ivory. These are reproduced as 



