PLATE XV. 



FIG. 



1. BuGULA GRACILIS, var. uncinata; p. 86, nat. size. 



1 «• , a single cell, showing the position of the 



avicularium. , 



3. • , zooecia, front view. 



3. , dorsal surface. 



4. , prehensile appendages. 



4 a. —, primary cell and appendages. 



5. SciiizopORELLA vulgaris, p. 2-M ; showing the struc- 



ture of the cell. See Plate XXXVII. 



6- , var, with umbonate ovicell, and mucro on 



the front wall. 



7, 7 a. EsciiAROiDEs quincuncialis, p. 339; fragment, 

 magnified and nat. size. 

 7 b. , young cell. 



7 c. , ooecium and orifice, forming together 



the " mamillarv rising.^' 



