Classification of the Percoid Fishes. 145 



praemaxillary ramus without posterior expansion ; maxillary 

 concealed, without suprarnaxillary ; small teeth in the jaws, 

 none on the palate. Gill-membranes broadly joined to the 

 isthmus ; 6 branchiostegals ; 4 gills ; pseudobranchiae. 

 Praeoperculum with a strong spine at the angle; operculum 

 normal. Suborbitals ligamentous ; no mesopterygoid or 

 metapterygoid ; skull depressed, narrowed between and 

 expanded behind the orbits ; sphenotic with a curved pro- 

 jection, as in the Pinguipedidae ; occipital crest short and 

 parietal crests absent ; exoccipital condyles widely separated; 

 no basisphenoid ; mesethmoid ossified as an interorbital 

 septum. Post-temporal forked, but forming an integral part 

 of the skull ; supracleithrum slender, nearly horizontal, and 

 directed outwards ; postcleithrum a single slender rod ; 

 foramen between hypercoraeoid and hypocoracoid ; radials 

 large, flat, 3 in number, all on the hypocoracoid. Vertebrae 

 21 (7+14), compressed, especially posteriorly; neural 

 spines below the dorsal fin and haemal spines above the 

 anal bifid for reception of the basalia ; no ribs ; praecaudals, 

 except the first, with long epipleurals, the anterior sessile, 

 the posterior ones on short parapophyses. 



Principal genera : Callionymus, Synchiropus, Dactylopus. 



Fam. 2. Draconettidae. 



Evidently related to the Callionymidae, with which they 

 agree in the number of vertebrae, as I have ascertained by 

 counting the myotomes in Centrodraco * acanthopo?na, Rgn. 

 This species, from the North Atlantic, differs from Draconetta 

 of the North Pacific in that the dorsal spines are stout and 

 pungent, the second much the longest, and in the presence 

 of a single series of teeth on vomer and palatines. I have 

 ascertained that the pectoral radials are large, elongate as 

 in Callionymus. The family differs externally from the 

 Callionymidae in the absence of a lateral line, the entire 

 praeoperctilum, and the reduction of the operculum and 

 suboperculum to a pair of strong spines ; in the last feature 

 these fishes resemble Harpagifer. 



* This generic name is here proposed for the first time. 



Ann. & Mag. N. Hist. Ser. 8. Vol. xii. 10 



