Thirteenth division : Acanth. centrisciformcs. 



Two dorsal fins, the spinous short, the soft and the anal of mode- 

 rate extent. Ventral fins truly abdominal, imperfectly developed. 



One family only 44. Centriscid^, iii. p. 518. 



Fourteenth division : Acanth. gobiesociformes. 



No spinous dorsal ; the soft and the anal short, or of moderate 

 length, situated on the tail ; ventral fins subjugular, —-, with an 

 adhesive apparatus between them or entirely absent. Body naked. 



I. An adhesive apparatus between the ventrals. 



42. GouiEsocLD^, iii. p. 489. 



II. Ventrals none 43. PsYcnROLUiiDj;, iii. p. 516. 



Fifteenth division : Acanth. channiformes. 



Body elongate, covered with scales of moderate size ; no spine in 

 any of the tins; dorsal and anal long. No superbranchial organ, 

 only a bony prominence on the interior surface of the epitympanic 

 bone. 



One family only 39. OpniocEPnALiD^, iii. p. 468. 



Sixteenth division : Acanth. labyrinthibranchii. 



Body compressed, oblong or elevated, with scales of moderate size. 

 A superbranchial organ -in a cavity accessory to that of the gills, for 

 the purpose of retaining water. 



I. Dorsal or anal spines piesent, sometimes in great numb'^r. 



35. LABiRiNimci, iii. p. 372. 



11; Neither dorsal nor anal spines. 



36. LuciocEPHALn).a:, iii. p. 390. 



II. 

 Dorsal and anal fins developed. Vent in front of the ventrals. 

 Only one family 4. Aphbedoderidje, ii. p. 271. 



III. 



Body riband-shaped, with the vent near its extremity ; a short 

 anal behind the vent ; dorsal as long as the body. 



Only one family 28. LopnoTiD.a;, iii. p. 312. 



