PISCES. 169 



Mtis. Ad. Frid. Tab. 33, fig. 6. This species lives in the Red Sea and 

 in the Indian Ocean, like Platax teira Guv., Chcetodon teira Bloch 1. 1, 

 fig. r, with which Bleeker unites Platax vespcrtilio japonicus Schleg. 

 Faun. Japon., Pise. Tab. 43. The length of the dorsal and anal fins can- 

 not supply a character, since these fins in old individuals become obtuse 

 and rounded. See P. Bleekek in the Verh. van lid Batav. Genootschap 

 XXIII. Deel, 1850. 



Platax arthriticus Cuv., Chcetodon arthritlcus W. Bell, Philos. Transact. 

 for 1793, PI. 6; Sumatra, Java. The skull is remarkable from a thick, 

 high crest; many of the spinous processes and interspinal bones have 

 tubercles or soft bony swellings. This species attains a very conspicuous 

 size. 



Amongst the fossil fishes of Monte Bolea, with many other squami- 

 pennes, species also of this genus occur, as Platax altissimns Agass. 

 Poiss. foss. IV. PI. 41. 



Chcetodon L. (excl. of some species^). Body oval, often high. 

 Teeth in jaws setaceous, crowded. Gape of mouth smalL Ventral 

 fins distinct. Palate edentulous. 



Rock-fish. These fishes, mostly very beautifully coloured, of the 

 tropical seas, are very numerous. The form is various, and iu this 

 respect even the species of the sub-genera or smaller groups differ 

 from each other, so that there are transitions from the one form to 

 the other. Four principal gi-oups may be distinguished, round each 

 of which other smaller sub-genera arrange themselves. 



a) Prceopcreulum armed at the lotver part with a large spine directed 

 hackivards, 



Holacanthus Lac. (and Pomacanthus ejusd.). Dorsal fin sino-le 

 caudal fin mostly rounded. 



Sp. Cluetodon armatus L., Mas. Ad. Frid. Tab. 33, fig. 5, Bloch Ichth. Tab. 

 201, fig. 2; this and some other species with a very high body, and in 

 that case without spinous rays in the dorsal fin {Pomacanthus Cuv.), are 

 from South America. — Others have an oval bod}^, with a great number of 

 spinous rays in the dorsal fin (13—15), and the prseoperculum with a margin 

 usually toothed (Holacanthus Cuv.). Of this division species are found in 

 both hemispheres ; ex.gr. in the gulph of Mexico: ChcEtodon ciliaris L., 

 Mus. Ad. Frid. Tab. 33, fig. i, Bloch Ichth. Tab. 214, Gubrin Iconogr., 

 Poiss. PI. 23, fig. I ; — Chcetodon nicoharcensis Bl., Schn., Holacanthus geo- 

 metricus Lacep., Cuv., Bloch Syst. Ichth. Tab. 50 (a small elegantly 

 marked species), and Chcetodon imperator Bloch Ichth. Tab. 194, Encycl. 

 Meth., Poiss. PL 93, fig. 284, are on the other hand from the E, Indies. 



1 Compare above, Dascyllus, p. 132, Acanthurv.s, p. iig;—CJiwtodon saxatilis L. 

 and Gh. rotundus L. belong to the genus Glyp>hisodon Lac, p. 132. 



