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ALLAX HANCOCK PACIFIC EXPEDITIONS VOL. 15 



Fig. 11. Parasagittal section of the female copulatory apparatus 

 of Aquaplana oceanica, showing remainder of female 

 apparatus. 



Fig. 12. Anterior end of mature specimen of Prosthiostomum 

 parvicelis, showing eye arrangement. 



Fig. 13. Anterior end of juvenile Prosthiostomum, presumably 

 parvicelis, showing eye arrangement. 



Fig. 14. Lengthwise section of everted male apparatus of P. 

 parvicelis. 



