Petromyzo7iidac 9 



the tiesh. They breed in the sprhig or early summer, when they 

 make a sort of nest by clearing the stones away from a circular or 

 oval space ; the eggs are shed in the sand at the bottom of the 



Pio. 2. Sea IjAmtrkv. 



nest and develop into a larva [Aniiitocoefes), which has neither 

 suctorial disc nor teeth, and lives in the sand like a worm ; these 

 larvae are called Prides. After three or four years of larval life, 

 when the Prides are 4 to 6 inches long, the metamorphosis into 

 the adult form takes place. 



I. Sea Lamprey, Pctromyzon marinus (fig. 2). — This species 

 has the suctorial disc completely covered with series of teeth 

 (fig. 3a) ; its marbled or spotted coloration is also distinctive. It 



Fig. .3. — Mouth and Suctorial Disc of (A) Sea Lamprey and 



(B) Lampern. 



attains a length of 3 feet and a weight of 5 lbs. or more. It occurs 

 on both sides of the North Atlantic and in the Mediterranean, 

 preying upon Cod, Mackerel, etc. In the spring or summer the 



