EXPLANATION OF PLATE XVII. 



Figure 86. — Potamilla oculifera, (p. 617;) in its tube, with branchiae fully expanded, 

 from a living specimen, found at Eastport, Maine. 

 87. — Cistenides Gouldii, (p. 612;) lateral view. 

 87a. — The same ; head and branchiae, dorsal view. 

 88. — Sabellaria vulgaris, (p. 611;) lateral view. 

 88a. — The same ; view of the operculum and tentacles, from above. 



(Figures 84, 88, 88a -wero drawn from nature, by J. H. Emerton ; 87, 87a by A. E. Verrill.) 



