^^^ PISCES. 



Platax. 



A row of trenchant teeth, each divided into three points, in front of 

 the others, or brush-like teeth; the body, strongly compressed, seems 

 to be continued into thick, vertical, elevated and scaly fins, in whose 

 anterior edge some few spines are concealed, so that the whole fish 

 IS much higher than it is long; very long ventrals. The Indian 

 Ocean. (1) 



One species, Ch. arthriticus, Bell. Phil. Trans., 1793, pi. vi, 

 of a more orbicular form, is remarkable for the knots or en- 

 largements in some of its interspinals and spinous apophyses.(2) 



A fossil species of this subdivision has also been discovered 

 at Mount Bolca.(3) 



PsETTus, Commers. 

 Figure similar to that of a Platax, but the teeth are very small and 

 crowded, and the ventrals reduced to a single small spine, without 

 soft rays. 



The form of some is elevated;(4) that of others round or oval;(5) 

 they are all from the Indian Ocean. 



PiMELEPTERUS, LaCCp. 



Distinguished from all other fishes by a single range of teeth placed 

 in a horizontal base or heel, on the anterior edge of which is a part 

 vertical and trenchant. The body is oblong, the head obtuse, and 

 the fins thickened by the scales which cover them; from which cir- 

 cumstance their name is derived.(6) They are oval, smooth, and 

 covered with brown scales; they inhabit both oceans.(r) 



(l)Chxt. vespertilio, BI., 199, 2;-Ch. tfira, lb., 1;_CA. guttulatus, Cuv. Ren 

 II, XXIV, 129. * 



(2) It is also the Ch. pentacanthe, Lacep., IV, xi, 2, and the Ch. orbicularis, 

 Forsk., or Manthinion orbiculaire, Lacep. IV, 500. 



(3) Ittiol. Veron., pi, 4 and 6. 



(4) Psett. Sebse, Cuv., Chsetodon rhombeus, Bl, Schn., Seb,m xxvi 21 Ps 

 rhombeus Cay., or Scomber rhombeus, Forsk., or Centrogaster rhombeus, Gm., or 

 Centropode rhomboidal, Lacep., Russ., 59. 



(5) Psett. Commersonii, Cuv., or Monodadyle faldforme, Lacep., H, v, 4, and HI, 

 131, which very probably does not differ from the Ch^t. argenteus, L., ov Acantho- 

 pode argente, Lacep. 



{.6) Pimelepterus (fat fin). This genus of Lacdp^de, IV, 429, formed from 

 Boscis the same as that of Xisterxs, V, 484, formed from Commerson; and 

 there is every reason to believe that the Dorsuaire, Lacep., V, 482, which is 

 certemb. identical with the Ktphosk, IU, 114, may very possibly also be the same 

 as the XisTERtJS. 



(r) The PimelopVere bosquien, Lace'p. IV, ix, 1 , or Chxtodon cyprinaceus, Brous- 



