FISHES 63 



do Jaw without horny plate. 



Ci Teeth usually 5-5. 



fi Lateral line complete; in California 6. Lavinia. 



£2 Lateral line incomplete; in the eastern and 



central States 7. Chrosomits. 



Co Teeth 4-4. 



fi First ray of dorsal fin not peculiar 8. Hybognathiis. 



U First ray of dorsal fin separate and joined 



with the other rays by a membrane 9. Pimcphales. 



Digestive canal short, less than twice the length of the body; 



peritoneum usually pale; carnivorous fishes. 



bi Teeth mostly blunt and enlarged, but slightly hooked; 



large fishes on the Pacific slope. 



Ci No barbels present 10. Mylopharodon. 



c-> Barbels present 11. Mylocheilus. 



hi Teeth slender, hooked; species mostly not on Pacific slope. 



Ci Teeth in the main row 5-5 or 4-5. 



di Barbels present, often very small. 



ei Tail symmetrical 12. SemotUus. 



eo The upper lobe of tail longer than the lower; 



in California 13. Pogonichthys. 



do Barbels absent. 



ei Abdomen behind ventral fins rounded and scaly. 



fi Teeth two-rowed, usually 2 teeth being in 



the lesser row. 



gi Size very large, the length being over 



1,000 mm 14. Ptychocheilus. 



g2 Length not over 400 mm. 



hi Caudal peduncle very long and 



slender 15. Gila. 



ho Caudal peduncle stout 16. Leiiciscus. 



U Teeth one-rowed, being either 4-5 or 5-5. 



gi In the extreme western States. 



hi Rays of dorsal fin 8 17. Rutilus. 



18. Hcsperoleucus. 



ho Rays of dorsal fin 10 19. Luxilinus. 



g2 In the central and southeastern States . 20. Opsopceodus. 



Co Abdomen behind the ventral fins acute and 



scaleless 21. Abramis. 



Co Teeth in the main row 4-4, the lesser row being often 



absent. 



di Lower jaw normally formed. 



Ci Barbels absent. 



fi Mouth not like that of a sucker. 



gi First (rudimentary) ray of dorsal fin 



separated from next ray, to which it is 



joined by a membrane 22. Cliola. 



go First ray of dorsal fin closely joined to 



the next. 

 s 



