Figure I|.3» Section of intestine of migrant sea lamprey; 

 male; total length — 16.3 inches; color of 

 liver— yellow- green. X23.2. 126 



Figure Ui. Section of intestine of migrant sea lamprey; 

 female; total length— 15-8 inches; color of 

 liver — ^bro-vm-green, X23.2 127 



Figure h^. Section of intestine of migrant sea lamprey; 

 female; total length — 16.9 inches; color of 

 liver — dark green. X23.2 12? 



Figure lt.6. Section of intestine of migrant sea lamprey; 

 female; total length — 15.9 inches; color of 

 liver — dark green. X23.2 128 



Figure Ii7. Section of intestine of spawning sea lamprey; 

 male; total length — ll|..6 inches; color of 

 liver — light green. X23.2 .....„...„ 128 



Figure U8. Section of intestine of spawning sea lamprey; 

 female; total length — 17.8 inches; color of 

 liver — dark green. X23 .2 129 



Figure 1|9. Raceway used in Ocqueoc River to determine 

 length of hatching period and production of 

 lairvae from the redds 138 



Figure $0. Frequency distribution of the total lengths 

 of 222 recently-hatched sea lamprey larvae 

 constituting the entire "hatch" from one nest lltO 



Figure ^1. Backwater along the bank of the lower Ocqueoc 

 River. A high concentration of arnmocoetes was 

 present in this bed. The bottom type was of 

 muck and silt containing much organic debris lU2 



Figure 52. Eddy along the margin of a deep gravel-bottomed 

 pool in the lower Ocqueoc River. Muck and silt 

 deposits as much as 1 l/2 feet deep harbored 

 great numbers of lamprey larvae Il4,2 



Figure 53- Distribution of the sizes of larvae taken from 

 two beds of differing characteristics in 

 the Ocqueoc River ,...,. 1)|) | 



Figure 5ii. Composite sketch of larval lampreys as they were 

 observed in thin-section aquaria resting or feed- 

 ing in their burrows. One individual is expelling 

 a cumulated detritus from its sieve apparatus li|.7 



vii 



