130 CLASS XIV. 



Spine-finned. This order of fishes is the most numerous of all. The scales 

 are in most furnished with fine spines or points at the posterior margin 

 {Ctenoides Agassiz). The ventral fins have commonly a hard pointed ray, 

 hke the first rays of the dorsal and anal fins ; they are placed in almost 

 all under or in front of the pectoral fins, and only in few behind these, as is 

 the case in so many malacopterygians. 



+ Loioer pharyngeal hone unpaired. {Pharyngognathi acanthopterygii 



MUELL.) 



Family XXVIII. Chromides. Pharyngeal bone divided by a 

 longitudinal suture into two lateral portions. Dorsal fin single. 

 Ventral fins placed under pectorals. Scales almost always ctenoid, 

 often large. Fleshy lips duplicate. Branchiostegous membrane 

 with five rays. Pseudobranchise none. 



Etro^lus. Teeth of jaws arranged in a double row with acute 

 margin exsert or tripartite. Anal fin with several (11 — 13) pun- 

 gent rays. 



Sp. Etroplus corucTii Cuv. et Val. Poiss. v. PI. 136; — Etroplus macidatus 

 Cuv., Chcetodo7imaculatus 'Block, Ichih. Tab. 427; East Indian fresh- water 

 fishes, which were placed by CuviEB in the family of the Sciwnoids with 

 Plyphisodon Lac. 



Chromis Cuv. (in part) Acara, Heros, GeojyJiaffus, Chceto- 

 hranchiis Heck. Body compressed. Teeth of jaws thin, conical, 

 crowded, forming a band, with front row somewhat larger. Lateral 

 line interrupted, anterior part convex, parallel to back, posterior 

 straight in the middle of tail. Dorsal, anal and ventral fins acumi- 

 nate, with some rays produced into filaments. 



Sp, Chromis niloticus Cuv., Ldbrus niloticus Hasselq., Iter Palcest. p. 346. 

 SoNNiNi Voyage en Egypte, PI. 27, fig. i ; this fish, named Bidti or Bolti, 

 is, according to Hasselquist, the best in the Nile, and reaches a size of 

 1' . The head is broad and thick. This species has cycloid scales, whilst 

 in the other species they are ctenoid. This Chromis, or another nearly allied 

 species, occurs also in South Africa : Tilapia Sparmanni Smith ; comp. 

 J. Mueller in Erichson's Archivf. Naturgesch. 1S43, pp. 381, 382. 



Chromis Gronovii, Acara Gronovii Heck., Lahrus brmieus Gbonov. 

 Mus. Ichth. p. 36, Zoophylac. Tab. V. fig. 4, (probably not specifically 

 diflierent from Lahrus punctatus L., Bloch Ichth. Tab. 295, fig. i) from 

 Surinam; the head and the anterior part of the back very thick and 

 round. 



Here belong difierent species of S. American fresh-water fishes, on which 

 compare Heckel Ann. des Wiener Museums, 11. 1840, s. 337 — 407. 



Here also belong the genera Uaru, Symphysodon, Pterophyllum and 

 Batrachops of the same writer. 



