PLATE IV. 



Alcyonella flabellum and Alcyonella Benedeni. 



Fig. 



1. Alcjionella jlahellum. Natural size. 



2. The same magnified. 



3. A young specimen of the same magnified, with the two valves of the statoblast still 



adhering to it. 



4. Longitudinal section of upper part of the cell of A. flabellum, showing certain anatomical 



details. 



5. Alcyonella Benedeni ; a portion of a specimen. It is drawn of the natural size. 



6. A portion of the same magnified. 



7. Free statoblast of ^. Benedeni; more convex face. 



8. The same ; less convex face. 

 9- The same, viewed on the edge. 



10. Adherent statoblast of A. Benedeni ; it is surrounded by a portion of the unorganized 



cement, by which it adheres to the walls of the cell. 



11. Young specimen of A. Benedeni, with the separated valves of the statoblast still attached 



to it. 



