PLATE LXXVIII. 



FIG. 



1. HippuRARiA Egertoni, p. 549; portion of the erect 



stem, with whorls of cells. 



2. , a zooecium, much enlarged, showing the 



ventral aperture. 



3. , showing the degree in which the cell can 



be bent. After a sketch by Sir P. Egerton. 



4. , nat. size *. 



5. Farrella repens, p. 529. After Van Beneden. 



6. , form ELONGATA. Ditto. 



* Figs. 1, 2, and 1 are after Busk. 



