igi 



Bampreys. 



THE Lampreys, Lamperns, or "nine-holes," as in some places they are termed, belong- to 

 a very remarkable family of fishes. ■ From their habit of attaching- themselves to stones 

 or other submerged bodies, they have received the name of PdromyzontidcE, which in Greek 

 signifies "stone-suckers," a term aptly proposed by Artedi. The body is -worm-like, C3-Iin- 

 drical, and limbless ; the skeleton is imperfectly developed, being cartilaginous ; the notochord 

 is persistent through life; there are no ribs, and no real jaws; the skin is without scales 

 and lubricous; the fin-fold of the tail is destitute of fin ra3^s ; the gills have no branchial 

 arches, and are formed like little pockets or pouches. The mouth is of very peculiar 





Sucker of Lamprey. 



structure, of circular form in the adult fish, suctorial, and armed with either simple or 

 many-pointed teeth of horny consistency. The nasal cavities do not communicate with the 

 throat ; the gill-pouches, with their external holes or openings, are seven in number, situated 

 on each side of the neck, so that the popular name of "nine-holes" is an erroneous one. 

 The respiratory apparatus is very peculiar; fishes as a rule admit water through the mouth 

 and emit it through the branchial slit, or gill opening ; the Lampreys fix themselves to 

 submerged bodies by their suctorial mouth, so that when in such a position it is obvious 

 that no water can be admitted through the mouth. How then is the water admitted so as 

 to oxygenate the blood of the gill-pouches? The water is alternately received and expelled 



