Classification of the Perooid Fishes. 125 



Finn. 33. Monodactylidae. 



This family includes -"» genera with the body deep and 

 strongly compressed, the dorsal and anal long and covered 

 with scales, the former preceded by ."> to 8 graduated spines, 

 the latter by 3, and the pelvic tins small or even vestigial, 

 inserted below the pectoral-. Month normally formed, 

 terminal, oblique, protractile, with small villiform teeth iu 

 the jaws and on the palate; maxillary exposed distal ly, 

 without supramaxillary. Gill-membranes free from the 

 isthmus. A strong occipital crest extending forward to the 

 anterior margin of the frontal s. Vertebrae 24 (10 + 14 ; 

 praecaudals with parapophyses from the third or fourth ; 

 ribs, except the last pair, sessile, inserted behind and above 

 the parapophyses. 



The recently described Bramichthys (Waite, Rec. Austral. 

 Mus. vi. ]>. 7:2, pi. xiv.) differs from Monodactylus in the 

 cycloid scales, and in the normally formed pelvic fins with a 

 scaly axillary process. Monodactylus has the body ovate or 

 nearly circular and the pelvic fins very small, with a short 

 stout spine and no axillary process ; a subocular shelf is 

 present and the pelvic hones are merely coalescent by their 

 inner edges. Psottiis differs not only in the very deep and 

 abnormally formed body, but in the absence of a subocular 

 shelf ami the ankylosis of the pelvic bones. 



The Eocene Amphistium may belong to this family. 



Fam. 34. Pempheridae. 



Except for the shortness of the dorsal fin Pempheris shows 

 considerable resemblance to the Monodactylidae (especially 

 Bramichthys) in external characters. The head-skeleton is 

 very like that of Monodactylus, but the pectoral arch differs 

 in the greater expansion of the hypocoracoids. The vertebrae 

 number 24 (10+14), the caudals rather elongate; the 

 anterior ribs are sessile, but the last 5 are inserted on 

 well-developed parapophyses. 



Fam. 35. Toxotidae. 



Dorsal rather short, above the anal, preceded by 5 strong 

 spines ; soft dorsal and anal scaly ; pelvic fins well developed, 

 below the pectorals, with scaly axillary process. Month 

 rather large, terminal, oblique, protractile, with small villi- 

 £orm teeth in the jaws and on the palate : maxillary very 



