ACANTHOPTERYGII 



695 



on the scapula and on 3 or 4 large, hour-glass or anvil-shaped 

 pterygials, two of which are in contact with the coracoid. 

 Ventral fins close together, with 1 spine and 3 to 5 soft rays. 

 Spinous dorsal strong, usually longer than the soft, sometimes 

 extending on the head ; anal usually with 3 spines. Body 

 covered with scales or naked. 



A large family of carnivorous marine fishes, some descending 

 to great depths, of nearly world-wide distribution, represented by 

 three extinct genera (Ampheristus, Histiocephahis, Scorpaenoides) 

 in the Eocene and by several species of Scorpaena in later forma- 

 tions. About 250 recent species are known. Principal genera: 

 Sebastes, Setarches, Scorpaena, Pterois, Apistus, Minors, Pelor, 

 Choridactylus, Centropogon, Gymnapistus, Aviblyapistus, Pen- 

 taroge, Tetraroge, Gnathacanthus (Ifoloxenus), Agriopus, Synancia, 

 Polycaulus. 



LLU 



FIG. 424. Scorpaena grandicornis. (After Valenciennes.) 



Great variety of form obtains in this family, from the Perch-like 

 Sebastes to the extraordinary -shaped Tetraroge, Pelor, and Synancia. 

 Many of its members are excellent examples of mimetic adapta- 

 tion to the surrounding, resembling the rocks among which they 

 live and being covered with dermal appendages simulating weeds. 

 An interesting example of commensalism has been discovered by 

 A. Alcock 1 in Minous inermis, off the coasts of India, which, 

 wherever found, is always more or less incrusted with the Gymno- 



1 Ann. Mag. Nat. Hist. (6), x. 1892, p. 212, and Zool. Gleanings Investigator, 

 1901, p. 41. 



