Class (fical ton of Teleostean Fishes. 81 



t No bouy stay for the praeopereulum. 



Pelvic fins subthoracic, thoracic or jugular, 



each of 5 or 6 rays, the first of which 



is spinous ; ribs, if present, normal ; 



prneinaxillaries more or less protractile ; 



opisthotic not enlarged 26 a. Percoidei. 



Pelvic fins subthoracic or thoracic ; ribs 

 normal ; prsemaxillaries not protractile, 

 typically produced and pointed; opisth- 

 otic not enlarged 26 6. Scombroidei. 



Pelvic fins thoracic ; ribs expanded, forming 

 a series of juxtaposed rings enclosing 



the air-bladder 26 <". Kurtoidei. 



Pelvic fins thoracic ; opisthotic enlarged, ex- 

 tending downwards lo the basi occipital . 26 d. Gobioidei. 

 Pelvic fins juoular or mental, each of 1 to 4 

 rays, the first of which may be spinous ; 

 parasphenoid sending up a wing on each 

 side which is joined by suture to the 



frontuls 26 e. Blennioidei. 



tt Third suborbital produced to or towards the prae- 

 opereulum § 26/. Scorpsenoidei. 



** Spinous dorsal modified into an adhesive disc placed 

 on the head 27. Discocephali. 



^. Post-temporal simple, rod-like, directed outwards, at 

 right angles to the horizontal, backwardly directed 

 supra-cleithrum ; cranium depressed ; pterygoids reduced 

 to a single small element united to the quadrate ; ribs 

 attached at the extremicies of sessile epipleurals ; an 

 adhesive ventral disc bounded posteriorly by the post- 

 cleithra, which meet in the middle line and are attached 

 to the pelvis 28. Xenopteri. 



y. Post-temporal, if present as a distinct element, small, 

 simple, suturally united with the cranium ; ribs absent ; 

 gill-openings reduced. 



* Pelvic fins, if present, subthoracic or thoracic ; parietal^ 



absent 29. Plectognathi , 



Post- temporal distinct, suturally united with 

 the pterotic ; supra-cleithrum vertical ; 



pectoral pterygials not enlarged 29 «. Balistoidei. 



Post-temporal co-ossified with the pterotic ; 

 supra-cleithrum oblique or horizontal ; 

 lower three pectoral pterygials en- 

 larged 29 6. Tetrodontoidei. 



** Pelvic fins, if present, jugular : parietals present ; 

 pectoral pterygials elongate. 



30. Pediculati. 

 Spinous dorsal normal ; epiotics separated 

 by the supraoccipital ; epipleurals pre- 

 sent ; 4 or 5 pectoral pterygials 30 a. Batrachoidei. 



Spinous dorsal, if present, modified in struc- 

 ture and position, the anterior rays on 



§ Except in the Comephoridse, which have the skeleton feebly ossified. 

 Ann, & Mag. N. Hist. Ser. 8. Vol. iii. 6 



