CYCLOSTOMATA 



427 



ment, or attached to stones by the buccal funnel. In the spring 

 the Sea-Lamprey ascends the rivers to spawn, and, after deposit- 

 ing its eggs in furrows which it excavates in the river -bottom, 

 it returns to the sea. The river-Lampreys spawn in the smaller 

 streams and brooks. The North American Brook -Lamprey, 



Fio. 243.— Spawning of the Brook-Lamprey (P. loilderi). On the right side of the figure 

 a male is attached to the head of a female. (From Bashford Dean and F. B. 

 Sumner. ) 



Petromyzon (Zampetra) wilderi, which is found in the neighbour- 

 hood of New York, deposits its eggs on the gravelly bottom of 

 a brook, in a small gravel-filled hole lying between a number 

 of large rounded stones^ (Fig. 243). In the vicinity of the 

 "nest" some ten to twelve Lampreys congregate, the males, 

 however, being much more numerous (five to one) than the 



^ Bashford Dean and F. B. Sumner, Trans. N. X- Acad. Sd. xvi. 1897, p. 321. 



