EXPLANATION OF PLATE 1. 



Fig. 1. Pohiclora (Leucodore) ciliata, -witli ova, from a photomicrograph, highly magnified. 

 Original. 



„ 2. Young larvse of PoJydora from a photomicrograph, taken shortly after its escape 

 from the ova-sac, highly magnified. Original. 



„ 3 & 4. Older stages, from a photomicrograph, highly magnified. Original. 



„ 5 to 9. Somewhat more advanced, after Prof. A. Agassiz. 



„ 10, Egg-cases of Poli/dora, attached to the side of the membranous tube, x 7 diameters. 



