Ver rut rv Hocrcc vurt. 



Proo. Roy. Soo. Vol.45. PI. 3. 



Fxg .1. 



SCHEME C . 



HARFLEUR 



Th& escLstunn Training 

 Walls step aJb EervULe,. 



Portu/rv of Charts 

 lelow L.W.O.5.T. 



Fig . 2. 

 SCHEME D 



HARFLEUR 



Fig . 3. 

 SCHEME D bis. 



