166 ANATOMY OF VERTEBRATES. 



plates in tlieir interspace articulate directly with the coracoicl. A 

 similar arrangement obtains in the Gurnards and the Wolf-fish ; 

 Ijut the carpals in the interspace of the radius and ulna are sepa- 

 rated from the coracoids by a space occupied by clear cartilage ; 

 and in the Wolf-fish the intermediate carpals are almost divided 

 by two opposite notches. The ulna is perforated in all these 

 fishes. The radius is of enormous size in the Opah (Lampris), the 

 Cock-fish, fig. 38, and the Flying -fish ; it is anchylosed with the 

 coracoid in the Silurus, to give firmer support to the strong 

 serrated pectoral spine. Both radius and ulna are connate with 

 the coracoid in the Angler {Lophius, fig. 102, 54, 55). 



The ossicles called carpals are usually four or five in number, 



102 



Coracoid anil lionce of pectoral fin, Angler {Lupliiu.^') 



as in the Cod tribe, fig. 81,56; they progressively Increase in 

 length from the ulnar to the radial side of the carpus, especially 

 in the Parrot-fish {Scarus) and the INIullets {M/if/il). They are 

 three in number and elongated in the Polypterus, fig. 103, sfi, 

 but arc reduced to two in number, and more elongated in the 

 Lophius, fig. 102, 56) ; thus they retain in this species and in the 

 Sharks, fig. 104, their primitive form of 'rays ;' but change to broad 

 flat bones in the Wolf-fish, just as the rays of the opercular fin 

 exchange that form in the Plagiostomes for broad and flat plates 

 in ordinary Osseous Fishes. 



The rays representing the metacarpal and pihalaiic/ial bones arc, 

 in the Cod, twenty in number, and all soft, jointed, and sometimes 

 bifurcate at the distal end. Tlieir proximal ends are slightly 

 expanded and overlap eacli otiier, but arc so articulated as to 

 ])ermit an oblicpie divarication of tlie rays to the extent permitted 

 by the uniting fin-membrane, the combined cftcct being a move- 

 ment of the fin, like that called the ' fealherintr of an oar.' Each 



