APPENDIX. 251 



weight of more than 110 pounds. It may be readily 

 understood, however, that it attains these large dimensions 

 only under very favorable circumstances, and fish of 20 

 pounds' weight are not very common. 



The gourami belongs to a family of fishes which has 

 always provoked interest by the singular adaptations for 

 holding supplies of water in peculiar reservoirs or organs 

 developed from the first of the gill arches, and which has 

 obtained for the family the name of fishes with labyrinthi- 

 forrn " pharyngeals," or Lcibyrinthiei. Like other bony 

 fishes, the gourami and its kindred have four cartilaginous 

 arches, and each of these bears on the external or convex 

 edge a gill which is double, or composed of two leaflets ; 

 behind these arches are two somewhat flattened bones, con- 

 tiguous at their internal edges, and bearing minute teeth, 

 called the lower pharyngeal bones, and above, connected 

 with the ends of the posterior gill arches, are other flat 

 teeth-bearing bones, known as the upper pharyngeals 

 these, too, are shared with most fishes ; but, in addition to 

 these, a peculiar superbranchial organ is developed from 

 the third or terminal portion, or articulation of the first 

 branchial or gill arch; this organ is composed of thin, 

 more or less expanded laminae, or leaflets, which form more 

 or less complicated chambers or cavities. These chambers 

 receive and contain a supply of water which furnishes 

 sufficient to moisten the gills and enable them to perform 

 their functions of aerating the blood long after the fish has 

 been isolated from the water ; this structure is also asso- 

 ciated with contracted branchial apertures or gill-holes, 

 while the gill-covers are closely appressed to the shoulders, 

 and the fish is thus enabled still better to eke out its sup- 

 ply of water. As a consequence of this beneficent pro- 

 vision, we find that the fishes of this family are enabled, 

 in an extraordinary degree, to sustain deprivation of water, 



