150 University of California Publications in Botany [Vol. 8 



ends and are probably reproducing since the contents seem more 

 or less broken up. There is no trace of a stalk (or tail) as in Codiolum, 

 nor is the shape that of the cell (or clava) of that genus. Therefore 

 it seems best to retain our Alaskan plant in Chlorochytriiini and to 

 refer it to C. Schmitzii pending further investigation of living material. 



The Whidbey Island plant referred here has also been carefully 

 reexamined. In the shape of the "clava" and in the occasional 

 possession of a stalk (or tail), it shows itself to be a Codiolum and is 

 discussed below under that genus. 



The Alaskan plant referred to this species varies in height 

 from 123/A up to 220//., and in width from 54/a to 66ju,, thus coming 

 within the measurements as given by Rosenvinge for Chlorochytrium 

 Schmitzii. 



3. Chlorochytrium Porphjrrae S. and G. 

 Plate 15, fig. 1 



Cells spherical, 40-60/x diam., embedded within the host on both 

 sides; chromatophore, single, at first small, covering the upper part 

 of the young plant, then increasing in size by sending out several 

 radiating arms and finally covering the cell wall; pyrenoid, single, 

 large, embedded within the chromatophore toward the upper part of 

 the cell; cell wall 2-3/x, diam., hyaline, not laminated; color, grass 

 green; sexual reproduction by 2-ciliated isogametes, 3-4ju, diam., fusi- 

 form to almost spherical, escaping singly through the oval opening 

 in the outer wall; asexual reproduction by zoospores and akinetes 

 unknown. 



Growing completely embedded within the outer membrane of 

 Porphyra perforata f. segregata Setchell and Hus. Washington (Cape 

 Flattery) to central California (San Francisco), 



Setchell and Gardner, in Gardner, New Pac, Coast Mar. Alg. I, 

 1917, pp. 379-384, pi, 32, f. 6; Collins, Holden and Setchell, Phyc, 

 Bor.-Amer, (Exsicc), no. 2280. 



This species was discovered at Lands End, San Francisco, Cali- 

 fornia, but since the first publication of its discovery it has been 

 observed in the vicinit}^ of Cape Flattery, Washington, where it grows 

 in abundance on the same host as at San Francisco, It probably 

 extends along our eoast wherever the host plant grows, 



A full account of the morphology and development of this species, 

 as well as an extended discussion of the status of Chlorochytrium and 

 the various plants referred to C. Cohmi, will be found under the refer- 

 ence to Gardner given above. 



