XVI 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, 
Fic. 243.—Spawning of the Brook-Lamprey (P. wilderi). 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 (Lampetra) wilderi, which is found in the neighbour- 
hood of New York, deposits its eggs on the gravelly bottom of 
a brook, in a small gravyel-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 
1 Bashford Dean and F. B. Sumner, Zrans. N.Y. Acad. Sci. xvi. 1897, p. 321. 
