210 FISHES. 



f Margin of upper jaw formed laterally by maxillaries ; lateral 



line inconspicuous ; small dusky fishes of muddy brooks ; 



usually a black bar at base of caudal. UMBRUXE, 101. 

 Jf Entire margin of upper jaw formed by interrnaxillaries ; 



head depressed ; small fishes of brackish or fresh waters, 



often barred or striped with black. 



CYTRINODONTIDJE, 100. 



FAMILIES OF ISOSPONDYLI. 

 * Body entirely scaleless ; deep sea fishes, 

 f No adipose fin ; throat with a long barbel ; pectorals rudi- 

 mentary Stomiatidce, the 8tomiatoids. 



ft An adipose fin ; no barbel ; belly with phosphorescent spots. 



Scopelidce, the Scopelids. 

 ** Body scaly ; head naked ; scales sometimes small and imbedded, 



sometimes large and deciduous. 

 \ An adipose dorsal fin ; belly rounded, 

 a. Margin of upper jaws formed by intermaxillaries alone. 

 6. Scales cycloid ; deep sea fishes. 



Synodontidce, the Synodonts. 

 bb. Scales ctenoid ; fresh water fishes ; no teeth on vomer or 



palate PERCOPSID^E, 104. 



aa. Lateral margins of upper jaw formed by maxillaries; 



scales cycloid ; in all waters. . SALMONID^E, 105. 



ft No adipose dorsal; lateral margin of upper jaw formed by 



maxillaries which are usually composed of three pieces; 



scales rather large. 



c. Abdomen compressed to an edge which is serrated ; lateral 

 line obsolete ; teeth very small or wanting ; in all waters. 



CLUPEHXE, 107. 



ce. Abdomen compressed but not serrated; jaws, vomer and 

 tongue with strong teeth; scales large, silvery; body 

 compressed ; lateral line well developed ; fresh water. 



HYODONTIIXE, 106. 



ccc. Abdomen rounded ; teeth various ; marine. 

 d. Upper jaw longest. 



e. Lower jaw toothless; sides with bright silvery band. 



e, the Anchovies. 



