FISHES — GYMNODONTIDAE — TETRAODON, 339 



Family GYMNODONTIDAE, Yan-ell. 



The skin is studded either with prickles or witli granules. The shape of the hody is short, 

 thick, and rounded in some, oblong and compressed in others. The ventral fins are wanting. 

 The snout is abbreviated and rounded. The mouth is rather small, provided with teeth of a 

 very peculiar structure ; there are either one or two in either jaw, resembling somewhat the bill 

 of a parrot, the teeth themselves being composed of laminae, which wear off and are at the same 

 time renewed. These laminae represent as many isolated teeth, which have combined into that 

 compact mass, occupying the whole extent of the jaws. 



Stn. — Gymnodontes, Cuv. Rt-gn. Anim. II, 1817, 145 ; 2d ed, 11, 1829 ; &, ed. illustr. Poiss. 334. — Mull, in Wie^m. Archiv 

 fiir Naturg. 1845, I, 134 & 137. 

 Gijmnodonlidae, Yarrell, Hist. Brit. Fish. II, 1836 ; &, 2d ed. 1841, 457.— DeKay, New Y. Faun. IV, 1842, 323.— 



Storer, Synops. 1846, 239. 

 Telraodontidae, Bonap. Sagg. Distr. metod. Anim. Vertebr. 1831, 120. 

 Gymnognathes, Dcm. Ichth. analjt. 1856, 157. 



The fishes of this family have only three branchial combs, or gills, a peculiarity of organization 

 occurring in but few others. The swimming or air bladder is composed of two regular, sym- 

 metrical, and approximated partitions, or lobes, within which small pouches, or compartments, 

 may be observed, giving rise to the idea that they were the analogues of the lungs. 



Most of the species, moreover, have the faculty of introducing atmospheric air into the 

 stomach, to swallow air, as it were, by which process they increase in bulk, and diminish at the 

 same time in specific gravity. In that condition they float motionless at the surface of the water, 

 occasionally reversed so as to keep the dorsal region downwards. Hence the vernacular appel- 

 lation of " balloon-fish," "globe-fish," "puffer," " swell-fish," &c. When caught, a sound 

 or grunt is heard, caused either by the escape of the air from the stomach, else by that of the 

 gases from the swimming bladder. We recollect having found sand, gravel, and pebbles to a 

 considerable size in the stomach of a species of Tetraodon from the Atlantic coast. 



TETfiAODON, Linn. 



Gen. Char. — Body short or elongated, with the abdominal region capable of much extension, and covered either wholly or 

 partially with prickles; else smooth or studded with granules. Jaws divided upon their middle by a vertical suture, presenting 

 the appearance as though four teeth were extant, two above and two below. 



Syn. —Tefraodon, Linn, Syst. Nature, ed. Xa I, 1678, 332; &, Mus. Adolph. Frid. 1764, 55.— Cuv. Regn. Anim. II, 1817, 

 147; 2d ed.' II, 1829; &, ed. II. 1829; &,, ed. illustr. Poiss, 337.— Storer, Rep. Fish Mass. 1839, 169; &, 

 Synops. 1846, 241.— Dk Kay, New Y. Faun. IV, 1842, 327.— Mull, in Witgm. Archiv fur Naturg. I, 

 1843, 330— DoM. Ichthyol. analyt. 1856, 160. 



The genus Tetraodon has recently been revised by J. J. Kaup in a catalogue, still MSS., of 

 the Plectognathi of the British Museum. Several new genera are proposed by him ; but their 

 description not having come to our knowledge, we are unable to tell at present whether the 

 following species belongs to the genus Tetraodon, as limited and characterized by that German 

 naturalist. 



