No. 552] 



THE SEA LAMPREY 



735 



tions, so similar is the movement to that of the rattle- 

 snake's tail. 



As to the length of time "fish" on a nest continue to 

 spawn, I was able to make some observations. The 

 nest shown in Figs. 1 and 4 was observed continuously 

 for over four hours, from 10 a.m. until after 2 p.m. ; and 

 during that time copulation took place at intervals 

 of from a few to ten minutes; and in all probability 

 would have continued several hours longer had the 



''fish" been left on the nest. Both became gradually 

 more and more scarred from seizing each other with 

 their mouths: round pale wounds stood out clearly 

 against the blue-black of the head of the female where 

 the male had repeatedly seized her; and large whitish 

 wounds could be seen on her back, especially posterior 

 to the first dorsal fin. The male likewise was scarred in 

 several places on the head and back. These scars are 



