348 LAMPREYS. 



OEDEE GG.-HYPEEOAETIA. 



(The Lampreys.) 



FAMILY CXVL PETROMYZONTID^E. 



(The Lampreys.) 



Body eel-shaped, naked; dorsal and anal fins long and 

 low, usually continuous with the caudal; mouth suctorial, 

 armed with horny teeth which rest on papillae. Eggs 

 small. 



These animals undergo a metamorphosis; the young 

 are usually toothless, and have the eyes rudimentary. 

 Genera five or six, in temperate regions, found in all 

 waters. They attach themselves to fishes and other ani- 

 mals, and feed by scraping off the flesh, by means of 

 their rasp-like teeth. 



The American species are still very imperfectly known. 

 Until quite recently the larvce were considered as form- 

 ing distinct genera, which have been termed Ammocoetes, 

 Scolecosoma^ Chilopterus, etc. 



* Maxillary teeth two, pointed, close together ; size large. 



PETROMYZON, 1. 

 ** Maxillary teeth single, bicuspid or tricuspid. 



AMMOCCETES, 2. 



/. PETROMYZON, Linnseus. LAMPREYS. 



1. P. marinas, L. GKEAT SEA LAMPBEY. Resembles 

 the next, but larger, with a shorter head, which is but 

 little longer than the "chest" (space occupied by the 

 branchial openings); color olive brown, mottled with 

 black ; L. 30 to 40. Marine, ascending rivers, eastward. 

 (P. americanus, LeS.) 



