(254) 



PLATE A. 



FIGS. 



1. Ventral surface of the pectoral fin of a flounder (Pleuro- 



nectes flesus Linn.), with thirty-two adult specimens of 

 Lepeophtheirus pectoralis (Miiller) adhering to it. 

 (x3.) 



2. Head of a whiting (Gadnn merlangus Linn.), with part of 



the operculum removed to shew an adult female Lerneea 

 branchialis Linn, adhering to the gills. ( x 2.) 



3. Part of the gills of a flounder (Pleuronectes flesus Linn.), 



shewing the "Cyclopoid" stage of Lernssa branchialis 

 attached to the ends of the gill-filaments. ( x 2.) 



(Reproduced from photographs.) 



