PLATE 18. 



Colpomenia sinuosa f. deformans Setehell and Gardner f. nov. 



13. Habit of a plant showing only a comparatively slight and uniform 



lobing. Original from Pt. Carmel, Monterey County, California, 

 (nat. size) 



14. Habit of a plant from the same spot as the preceding, showing the 



tendency towards unequal lobing. (nat. size) 



15. Habit of a group of plants of the type of the form. Any one of these 



plants may be separated and become the Scytosiphon bullosus 

 Saunders, (nat. size) 



Chordaria abietina Ruprecht. 



16. Habit of a group of very young plants, showing the horizontal lobed 



thallus, whence the young vertical thalli are arising. Original 

 material from Point Carmel, Monterey County, California, (a 

 little more than natural size) 



17. Habit of a plant just reaching the adult condition, showing the rela- 



tion between the horizontal and vertical thalli. From the same 

 place, (nat. size) 



Constantinea Sitchensis P. & R. 



18. Habit of a young plant, showing the method of producing the new 



blade by the appearance, at first, of a subulate projection in the 

 center of the old blade. Original material from Whidbey Island, 

 (about one -half nat. size) 



Constantinea simplex Setehell. 



19. Habit of a plant from Fort Ross, California, showing the first stages 



of the production of the new blade by the rosulate process, 

 (about one-half nat. size) 



20. Habit of a plant in which the process of producing the new blade is 



farther advanced, (about one-half nat. size) 



21. Habit of plant still farther advanced, (about one-half nat. size) 



All the figures were drawn under the direction of W. A. Setehell. 

 Figures 13-17 were drawn by H. N. Bagley, and the rest by 

 A. A. Lawson. 



[4001 



