LAMPREYS AND HAG-FISHES. 





LAMPREYS AND HAG-FISHES. 



The lampreys and hag-fishes stand on a higher level than do the forms 

 just mentioned. They are larger, eel-like animals which live principally 

 in the sea, although the lamprey goes into the rivers to lay md 



in some cases it may live in fresh water all its life. 



The lampreys, or lamprey-eels, of which there are several species, differ 

 from the true eels in many important points, only two of the superfii 



Fig. 290. — Lampreys (Petromyzori). 



ones needing mention here. In the true eels the jaws arc armed wil 

 row of teeth implanted in sockets, while the lamprey lacks I jaws, 

 has a circular sucking-mouth, the whole inside of which is 

 horny hooked teeth, each of which is planted on a little eleva 

 skin. The lampreys, again, have not a single gill-opening on 

 of the neck, but instead seven openings, as can be seen from i 

 the hag-fishes the number of gill-openings may vary from one 



