THE LAMPREYS 7 



have hitherto lived in the sand, and wander down 

 stream until they find some suitable spot, often at a 

 bend where the water runs slowly, where they burrow 

 in the sand or mud. 



The larvae, or Prides, as they are called in 

 England, differ greatly from the adults ; they are 

 toothless, with a small transverse lower lip and a 

 hood-like upper lip, and the entrance to the mouth 

 is guarded by a number of fringed barbels which 

 form a very perfect sieve. The eyes are hidden and 

 quite rudimentary, the small gill-openings lie in a 

 groove, and the fins are low. 



Each Pride forms a tube in the sand or mud in 

 which it lies ; the tube is usually open at the end, so 

 that the water flows in freely. When disturbed the 

 Prides worm their way through the sand and do not 

 wriggle out if they can help it ; they feed on minute 

 organisms. They probably live in this way for three 

 or four years, and when they are from 4 to 6 inches 

 long change into the adult form. 



It may here be mentioned that the Prides of the 

 different species of Lampreys are so similar that the 

 name Ammoccetes branchialis is applicable to all. 

 The name " Blind Lamprey " refers to their rudi- 

 mentary eyes, and that of " Mud Lamprey " to their 

 habit of remaining buried in the mud, whence they 

 may be dug out in quantities in small brooks if the 

 stream above be dammed up. 



The metamorphosis takes place in the autumn ; 

 first the eyes appear, and as they become more 

 evident the mouth is contracted, the upper and lower 

 lips join to form a single circular lip, and the fringed 

 barbels become reduced to simple papillae surround- 

 ing the mouth ; then the lips grow out to form the 



