166 PISCES. 



AxiNURus, Cuv. 



More elongated and without horn or knob, but with the same bran- 

 chial and ventral rays as in the preceding genusj each side of the 

 tail armed Avith a single, square, trenchant blade, without a shield; 

 the mouth very small and the teeth very slender.(l) 



PriodoNj Cuv. 



The notched teeth of Acanthurus, the three soft ventral rays of Na- 

 seus, and the unarmed tail of Siganus.(2) 



FAMILY X. 



This family is distinguished by 



LABYRINTHIFORM PHARYNGEALS. 



By this we mean, that part of the superior pharyngeals of 

 these fishes are divided into small irregular lamellae, more or 

 less numerous, intercepting cells containing water, which thus 

 flows upon and humects the branchicc, while the animal is re- 

 moved from its proper element. By this it is enabled to quit 

 the rivulet or pool, which constitutes its usual element, and 

 crawl to a considerable distance from it, a singular faculty, not 

 unknown to the ancients, (3) and which induces the people of 

 India to believe that they fall from heaven. 



Anabas, Cuv. 



It is in this genus that we find the greatest degree of complication 

 in these labyrinths; the third pharyngeals, however, have teeth en 

 paves, and there are others behind the cranium. Their body is 



Cuv., badly drawn, Ren. I, 178; — Nas. incornis, Cuv., Ren. I, f. 128, and not so 

 well, f. 147, probably the Acanthurus harpuras, Shaw; — Nas. carolinarum, Quoy 

 and Gaym. op. cit. pi. 63, f. 1; — Nas. tuber, Commers., or Nason-Loupe, Lacep., 

 Ill, vli, 3, or Acanthurus nasus, Shaw, Renard, I, f. 79, Valent, No. 119 and 478. 



(1) Axinurus thynnoides, Cuv., a new species brought by Quoy and Gaymard 

 from New Guinea. 



(2) Priodon annularis, Cuv., a new species brought from Timor by the same 

 gentlemen. 



(3) Theophrastus, in his treatise upon fishes which live out of water, speaks 

 of small ones which leave their native streams for some time and then return to 

 them, and says that they resemble a Mugil. 



