Classification of tie Percoid Fishes. 135 



teeth in jaws coalescent, forming a sharp-edged plate; 

 pharyngeals as in the Labridffi ; pharyngeal teeth granular, 

 forming a pavement. Dorsal spines flexible, numerous (16 

 to 24) ; each pelvic fin of a spine and 4 Boft rays. Scales 

 small or moderate ; lateral line continuous. Skull flattish 

 above, with a more or less distinct interorbital depression 

 for the reception of the praemaxillary pedicels : a short occi- 

 pital, hut no parietal crests. Vertebra? 36 to 53 ( 19-31 + 17- 

 22) ; all the ribs on parapophyses. 



Four genera : Olistherops, Coridodax, Odux, and Siphono- 

 gnathus, from the coasts of Australia and New Zealand. 

 Siphonognathu8 is a remarkable type, very elongate, with the 

 head like that of a Flstularia, and without pelvic fins. 



Fain. 3. Scaridae. 



Mouth non- protractile ; maxillary firmly attached to prse- 

 maxillary; dentary movably articulated with articular; jaws 

 short and powerful, with the teeth united to form a pair of 

 sharp-edged plates, recalling the beak of a parrot. Denti- 

 gerous portion of lower pharyngeal quadrangular, with 

 longitudinal series of transversely expanded linear teeth 

 forming a pavement ; upper pharyngeals similarly toothed, 

 produced upwards into vertical plates with thickened convex 

 upper edges moving backwards and forwards in a pair of 

 grooves on the parasphenoid. Scales large, about 25 in a 

 longitudinal series ; lateral line abruptly decurved or inter- 

 rupted posteriorly. Dorsal fin of 9 spines and 10 or 11 soft 

 rays, anal of 2 or 3 spines and 8 to 10 soft rays, pel vies of a 

 spine and 5 soft rays. Skull with occipital crest strong and 

 parietal crests well developed. Vertebrae 25 (9-10+ 15-16); 

 all the ribs on parapophyses. 



Scar us, Pseudoscarus, Callyodon, Sparisoma, &c., shore- 

 fishes of the tropics. 



Division 6. Gadopsiformes. 



Fam. Gado-psidae. 



GadopHs scarcely differs from the Perciformes in osteo- 

 logy, but there is uo mesopterygoid and there are 2 radials 

 on the hypercoracoid and 2 on the hypocoracoid. The 

 pelvic tins are jugular, each reduced to a small spine and 

 a bifid ray. Against Blennioid relationships are the inter- 

 vention of the prootic between parasphenoid and alisphenoid, 

 the 3 anal spines, the dorsal and anal rays more numerous 



