28 Univcrsiti/ uf Calif ornki ruhlications in Botany YWm^.^ 



lioinogeneoiis ; coll contents bright bliie-green or olive green when 

 young, changing to brownish when old; gonidia numerous, 2/i, diam. 



Growing on Chaetomorpha acrta in a tide pool near high -tide 

 limit. Cypress Point, Monterey County, California. January, 1917. 



Setchell and Gardner, in Gardner, New Pac. Coast Alg. II, 1918, 

 p. 4:39. pi. 37, figs. 22-24. 



The plants of this species were found associated with Xenococcus 

 Chaetomorphae and the two species were so abundant as to give the 

 host plant a very dark color. The shapes of the cells of D. pacifica are 

 determined, to a certain extent, by their position on the host and by 

 their age. The younger cells of C. aerea are cylindrical, but they 

 become quite torulose at maturity. This change in the shape of the 

 host cells modifies the form of certain cells of the epiphyte. If the 

 gonidia of the Dermocarpa happen to locate at the cross walls when 

 the host cells are young, increase in the size of the cells of both the 

 host and the epiphj'^te causes the cells of the epiphyte to become much 

 crowded and thus assume a narrow wedge shape. As the cells of the 

 host plant mature and begin to disintegrate the younger Dermocarpa 

 cells that have had more room in which to expand are liberated 

 and become broadly oval or even spherical. The cell contents become 

 much darker and brownish at maturity, and when mounted in glycer- 

 ine and acetic acid change to purple. The contents of the whole cell 

 change into gonidia by simultaneous division. 



7. Dermocarpa protea S. and G. 

 Plate 4, figs. 4, 5 



Cells extremely variable in shape and size, broadly pyriform to 

 narrowly cuneate, 40-120/* long, 6^0/x diam. at the apex, 3-7 /x at the 

 base ; cell wall hyaline, 2-3/a thick ; protoplast homogeneous, light 

 blue-green ; gonidia 3-3. 5/a diam. formed by successive divisions of 

 the protoplast. 



Growing on Spangomorpha sp. West coast of Whidbey Island, 

 Washington. 



Setchell and Gardner, in Gardner, New Pac. Coast Alg. Ill, 

 1918fl, p. 456, pi. 38, figs. 4, 5. 



A single specimen of this species of Spongomorpha with the above 

 epiphyte growing upon it has thus far been collected. The terminal 

 portions of tlic liost were so thickly clothed with the epiphyte as to 

 give them a very decidedly dark appearance. Microscopic examin- 



