178 ZOOLOGY. 



12. Polypterus. Gill'inembrane one rayed ; fins numerous 



along the back. 



13. Elops. Head amooth ; edges of the jaws and palate 

 rough, with minute teeth ; gill-membrane with thirty 

 rays, armed in the middle of the outer side with five 

 tooth-like processes. 



14. Argentina. Argentine. Tee//j in the jaws, and on the 

 tongue ; gill-memhrane eight rayed ; vent situated near 

 the tail ; ventral Jins composed of many rays. 



15. Alherina. Atuerine. Upper jaw ^^tiis\\ ; gill-mem- 



brane six rayed; a silvery line extending along the 

 sides. 



16. Mugil. Mullet. IBody and gill covers^ covered with 

 large scales : teeth on the tongue and palate ; above the 

 angles of the raouth a hard callous j gill-membrant 

 with six incurvated rays. 



17. Exocatus, Flying-Fish. Head covered with large 

 scales; gill-membrane with ten rays; pectoral Jins 

 very large and long. 



18. Poli/nemus. Heud compressedj covered with scales ; 



snout obtuse, prominent; gill-membrane five to ten 

 rayed ; pectoral fins with distinct, entire, cirri. 



19. Clupea. Herbino. TJearf compressed ; snout inclining 



