578 MALACOrTERYGII. 



(28) Gymnodontida, (Gr. naked-teeth.) BALLOON and GLOBE- 

 FISHES. 



These can scarcely be said to have real teeth ; but the jaws 

 are covered with enamel so divided into plates as to answer the 

 purpose of teeth. 



In the SEA PORCUPINE, Diodon, (Gr. two teeth,) each jaw has 

 a single piece ; hence the generic name. The form of this fish 

 is somewhat cubical ; it has the singular property of puffing 

 itself up into a globular ball, (Plate XIV. fig. 7,) and in this 

 shape floating on the surface. The length varies in different 

 species, from two to seven inches. In the Puffer or Balloon- 

 fish, Tetraodon, (Gr. four teeth,) the suture in the middle of each 

 jaw gives it the appearance of four teeth. Like the Diodon it 

 can inflate and contract itself at pleasure. When it inflates 

 itself the formidable spines with which the body is covered, be- 

 come erected. Its flesh is unwholesome if not poisonous. The 

 Puffer can bite severely, and can emit water in self-defence; its 

 spines are also an effectual guard, but the most curious thing 

 about it is that when handled, it emits a beautiful red excretion, 

 which stains ivory and paper a permanent carmine red. 



The small GLOBE-FISH, Acanthosoma (Gr. spiny body) cari- 

 natum, (Lat. ridged,) is armed with spines and susceptible of in- 

 flation, (Plate XIV. fig. 6.) It is quite small, being only one 

 inch in length. The color is of olive brown above, silvery be- 

 neath. The GLOBE FISH, T. tevigatus, (Lat. smoothed or pol- 

 ished,) is from one to two feet in length. The Common Puffer, 

 T. turgidus, (Lat. swollen,) is from six to twelve inches long. A 

 species of electrical Globe-fish, T. lineatus, is found in the Nile. 

 The SUN FISH, or MOON FISH, Orthagoriscus, (Gr. a sucking 

 pig,) appears as if the fins were set in or near the head, and the 

 tail abruptly cut off, so that its aspect is most singular. The 

 Sun-fishes are without spines, and have not the power of infla- 

 tion. A species found on the coast of France weighs over three 

 hundred pounds. 



Balistida, (Gr. from balista, a military engine resembling a 

 stringed bow.) FILE-FISHES. 



These are fishes of a less grotesque appearance than the Dio- 

 dons and Tetraodons, found most largely in the still waters of 

 tropical seas. The body is compressed and has a lengthened 

 conical or pyramidal snout, ending in a small mouth having dis- 

 tinct teeth in both jaws. The skin is roughened with scaly gran- 

 ulations or prickles ; in the typical forms there are two dorsal 

 fins ; in others, the front dorsal fin is sometimes represented by a 

 single spine. The ventral fins are often wanting or else indis- 



