414 



TEXTBOOK OF ZOOLOGY 



SUCTORIAL MOUTH 



NASAL OPENING 



\- EYE 



-GILL CLEFT 



V 



•DORSAL FIN 



-URINOGENITAL 

 PAPILLA 



CAUDAL FIN 



Fig. 223. — Lateral view of the Pacific lamprey, Entosphenus tridentatus. (Drawn 



by Titus C. Evans.) 



