210 FISHES. 



:}: Margin of upper jaw formed laterally by maxillaries ; lateral 

 line incoui^picuous ; small dusky iislies of muddy brooks ; 

 usually a black bar at base of caudal. Umbrid^, 101. 



:}::}: Entire margin of upper jaw formed by iutermaxillaries ; 

 head depressed ; small fishes of brackish or fresh waters, 

 often barred or striped with black. 



Cyprinodontid^, 100. 



FAMILIES OF ISOSPONDYLI. 



* Body entirely scaleless ; deep sea fishes. 



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

 mentary Stomiatidce, the Stomiatoids. 



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



Scojjelidce^ the Seojyelids. 



•=* 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 iutermaxillaries alone. 



b. Scales cycloid ; deep sea fishes. 



Synodontidce, the Synodonts. 



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

 palate Percopsid^, 104. 



aa. Lateral margins of upper jaw formed by maxillaries; 

 scales cycloid ; in all waters. . Salmonid^, 105. 



Xt 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. 



CLUPEIDiE, 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^, 106. 



ccc. Abdomen rounded ; teeth various ; marine. 



d. Upper jaw longest. 



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



^n.qrauUdce^ the Anchovies. 



