PLATE CXIV. 



FIGS. PAGE 



1. Arthrodesmus Incus forma perforate Sclimidle. 



x 500 . . . . 93 



2-4. -A Incus var. Ralfsii W. & G. S. West. 2 and 

 3, x 400 (after Ralfs ; 3, zygospore) ; 4, x 

 400 . . . . . 95 



5. A. Incus var. Ralfsii forma latiuscula W. & 



G. S. West, x 500 . . .96 



In fig. 5 c the delicate furcate processes are 

 gelatinous rods secreted by the protoplast, 

 each one being situated over one of the prin- 

 cipal pores in the cell-wall. 

 6. A. Incus var. Ralfsii forma subhexagonaW . & 



G. S. West, x 520 . . .96 



7. A. Incus var. subquadratus W. & G. S. West. 



x 520 . . . . 97 



8. A. Incus var. longispinus Eichler & Kacib. x 



520 96 



9-10.4. Incus var. valfdn* W. & G. S. West. x 



520 . . . . . 96 



11-13. A. triangularis Lagerh. 11, x about 400 



(after Lagerheim) ; 12 and 13, x 520 . 97 



14-15. A. triangularis var. inflatus W. & G. S. West. 



x 520 . . . . 99 



16. A. triangularis var. inflatu* forma rolusta W. & 



G. S. West, x 400 . .99 



17. A. triangularis. A form from the plankton 



with the cell twisted at the isthmus, x 500 . 98 



