46 



Arenicolidae 



The chaetae of A. marina, 'pusilla and assimilis possess, along one 

 side of their distal fourth or fifth, a thin lamina, which, in large 



r 





X80O 



i 



K 



Fig. 13. — A. marina(250 mm. long). A, Distal 

 fourth of a notopodial chaeta ; B, Tlie re- 

 gion marked + in A more highly magnified. 



I'ig. 14. — A. assimilis var. ajfinis (250 mm. 

 long, from Otago Harbour, N.Z.). A, Distal 

 third of a notopodial chaeta ; B, The re- 

 gion marked H- in A more highly magnified. 



