226 



THE LIFE OF CRUSTACEA 



many species, it re-acquires the power of swimming, 

 and specimens of Caligus, for instance, are commonly 

 found free in tow-net gatherings. 



D aa 



FIG. 73 STAGES OF DEVELOPMENT OF Lerncea branchialis. F is 



SLIGHTLY, THE OTHER FIGURES GREATLY, ENLARGED. (After 



A. Scott.) 



A, Nauplius, just hatched ; B, young female taken from gills of 

 Flounder ; C, free-swimming stage of female, after leaving 

 Flounder ; D, free-swimming male ; E, female just after settling 

 on gills of Whiting ; F, fully-developed female. 



On the gills of Cod, Haddock, and other common 

 fish, we often find a red worm-like parasite, Lerncea 



