LOPHOBRANCHIATES : SYNGNATHID^. 353 



SYNGNATHID.E, OR PIPE-FISH FAMILY. This Family 

 is usually made to include all the Lophobranchiates. 



The Genus Syngnathus Pipe-Fishes has the body 

 exceedingly elongated, slender, and covered with a series 

 of hard plates parallel to each other ; the snout prolonged, 

 with the mouth at the extremity ; no ventral fins ; and the 

 males of many species have Fj g . 23 i. 



a pouch for the reception 



Of the eggS, in Which the Pipe-Fish, S. Peckianus, Storer. 



young are hatched. Several species are known, five to ten 

 inches long, all inhabiting tropical and temperate seas. 



The Genus Hippocampus Sea-Horses has the body 

 short, compressed, covered with angular and Fig 232 

 spinous plates, neither ventral nor caudal fin, 

 a prehensile tail, and the head and neck have 

 some resemblance to those of a horse. Sev- 

 eral species are . known, from three to six 

 inches long, all marine. H. hudsonius, De- 

 kay, of the Atlantic coast of the United 

 States, is about five inches long. 



SUB-SECTION VI. 



THE ORDER OF PLECTOGNATHES. 



THIS Order comprises fishes whose chief characteristic 

 is that the maxillary bone is permanently attached to the 

 intermaxillary, which alone constitutes the jaw. 



GYMNODONTID.E. This Family embraces those whose 

 jaws are furnished with a bony substance resembling 

 enamel, and divided internally into laminae. These lam- 

 inae are really true teeth united, which succeed each other 

 as fast as they are destroyed by trituration. About sixty 

 species are known, all marine. 



The Genus Diodon has all the teeth united into one in 

 each jaw, and the surface of the body covered with spines. 



