L ( )2 TELEOSTEI. 1'H I8OSTO.M I. 



The rayed dorsal fin, if present^, belongs to the abdominal portion 

 of the vertebral column, ueing in advance of the veutrals. Adipose 

 fin present or absent. 



a. Length of the anal fin nearly equal to that of the caudal portion of 

 the vertebral column. Gill-openings wide. 



Teeth on the palate. Barbels four or six. 

 Rayed dorsal fin without spine ; no 

 adipose fin. Pectoral with a spine. Ven- 

 tral with eight or more rays ; anal with 

 from sixty to ninety rays. Air- 

 bladder free , 7. SILURUS. 



Teeth on the palate. Barbels eight. , Rayed 

 dorsal fin with a short spine, an adipose 

 fin; j&a pectoral spine. Ventral with 

 six, anal with from fifteen to about 



twenty-three rays. Caudal rounded or 



lanceolate. Air-bladder free 8. OLYBA. 



No teeth on the palate. Barbels eight. Dor- 

 sal fin with one spine and six rays ; a 

 small pectoral spine. Anal rather short 

 (eleven to twelve rays). Ventral with 

 six rays ; caudal forked. Air-bladder 

 enclosed in bone 9. AMBLYCEPS. 



Teeth on the palate. Barbels eight. A short 

 spineless dorsal, also an adipose fin ; an 

 elongated anal one (sixty to eighty rays). 

 A strong pectoral spine. Ventral with 

 six rays. An elongated, respiratory air- 

 sac, extending backwards amongst the 

 muscles of the back on either side of the 

 neural spines. Air-bladder enclosed in 

 bone 10. SACCOBRANCJU *. 



Cleft of mouth deep, extending to behind 

 the eyes. Teeth on the vomer. Barbels 

 four. Rayed dorsal fin short, spineless ; 

 no adipose fin. A pectoral spine. Ven- 

 tral with nine or ten rays ; anal with 

 sixty-five to ninety-five rays. Air- 

 bladder free " 11. WALLAGO. 



Teeth on the palate. Barbels eight. A short 

 dorsal fin with a spine, also an adipose 

 fin. A pectoral spine ; an elongated anal 

 fin (forty-seven to fifty rays). Ventral 

 with six rays. Air-bladder partially 

 protected by bone 12. EUTBOPIICHTHY.S. 



Cleft of mouth does not extend to the eye. 

 Teeth on the vomer. Barbels two or 

 four. Rayed dorsal fin when present 

 small ; no adipose fin. A pectoral spine. 

 Ventral with ten or less rays ; anal with 

 from about forty-five to ninety-five -rayt - 

 Air-bladder free .". . 13. GALLIC HBOUS. 



Teeth on the palate. Barbels eight. No 

 rayed dorsal, but an adipose fin. Pec- 

 toral with a spine ; an elongated anal 

 (sixty to seventy-five rays) ; a pectoral 



