Si 

 from ti 

 no peh 

 branchi 

 median, 

 without 

 appenda 

 continue 

 waters, 

 unlike th 



CHECK LIST OF THE 



Class MARSIPOBPAi^^''"' 



Nasal 



& 



tiie palate. 



Family PETROMYZONID^. (The Lampreys.) 



Body eel-shaped, subcylindrical anteriorly, compressed behind ; mouth 

 nearly qircular, armed with horny teeth which rest on papillae ; gill open- 

 ingrs seven, arranged in a row along the side of the "chest" ; lips present, 

 usually fringed; nostril on top of head, just in front of eyes; dorsal fin 

 more or less deeply divided by a notch; the posterior part commonly con- 

 tinuous with the anal around the tail ; intestines with a spiral valve ; eggs 

 shiall. 



The Lampreys undergo a metamorphosis, the larvae of all species 

 being toothless and having the eyes rudimentary. 



They attach themselves to fishes and feed by scraping off the flesh 

 with their rasp-like teeth. 



Genus ICTHVOMYZON. 



Lampreys with the supraoral lamina armed with two or three separate 

 teeth, pointed and close together, not forming a crescent-shaped plate ; 

 anterior lingual tooth divided by a median groove. The dorsal fin notched 

 but not separated into two portions. 



