210 FISHES. 



\ 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. UMBKID^E, 101. 

 ft Entire margin of upper jaw formed by intermaxillaries ; 

 head depressed ; small fishes of brackish or fresh waters, 

 often barred or striped with black. 



CYPRINODONTID^E, 100. 

 FAMILIES OF ISOSPONDYLI. 

 * Body entirely scaleless ; deep sea fishes. 



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

 mentary Stomiatida, the Stomiatoids. 



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. 

 b. Scales cycloid ; deep sea fishes. 



Synodontidm, 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.K, 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. 



CLUPEID/E, 107. 



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

 tongue with strong teeth; scales large, silvery; body 

 compressed; lateral line well developed; fresh water. 



HYODONTID^E, 106. 



ccc. Abdomen rounded ; teeth various ; marine. 

 d. Upper jaw longest. 



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



the Anclwmes, 



