1920] Sctchell-Gardner: Chlorophyceae 147 



West reduces Endosphaera Klebs, Scotinosphaera Klebs, Chloro- 

 cystis Reinhardt and Stoniatochyirium Cunningham to one genus and 

 unites that with Chlorochytrium Cohn. "They all agree in being 

 holophytic, unicellular, spherical or nearlj^ so, wholly or partly endo- 

 phytic plants with a single chromatophore, covering the wall more or 

 less completely and containing one or more pj^renoids. Reproduction 

 is by piano-gametes or by zoospores or by both" (cf. Gardner, 1917, 

 p. 383). It seems best to follow West in his conception of the genus 

 and our species are, consequently, assigned to Chlorochytriuyn in this 

 extended sense. The three species thus far credited to our territory 

 are immersed in the tissues of various membranous or expanded red 

 algae. 



Key to the Species 



1. Cells with apiculate tips 1. C. inclusum (p. 147) 



1. Cells without apiculate tips 2 



2. Cells spherical, chromatophores with one pyrenoid 



3. C. Porphyrae (p. 1.50) 



2. Cells clavate or ovoid, chromatophores with two or more pyrenoids 



2. C. Schmitzii (p. 149) 



1. Chlorochytrium inclusum Kjellm. 

 Plate 13, fig. 1 



Cells in the vegetative condition, spherical or subspherical, entirely 

 included within the host plant, at the time of the formation of the 

 zoospores, slightly elongated, depressed conical, ampullaeform, ovoid 

 or ellipsoid, at length exposed through the penetration of the cortical 

 layer of the host by the apiculate tip, emitting the zoospores through 

 an ostiole. 



Endophytic in the fronds of various membranaceous algae, e.g., 

 Iridaea, Weeksia, Const antinea, etc. Probably common along the coast 

 from Sitka, Alaska, to Puget Sound, Washington. 



Kjellman, Alg. Arctic Sea, 1883, p. 320, pi. 31, f. 8-17 ; Setchell 

 and Gardner, Alg. N.W. Amer., 1903, p. 206?; Collins, Green Alg. 

 N. A., 1909, p. 147 (in part) ; Collins, Holden and Setchell, Phyc. 

 Bor.-Amer. (Exsicc), no. 514?; Tilden, Amer. Alg. (Exsicc), no, 

 389?. 



The description, given above, is a fairly literal translation of the 

 Latin diagnosis of Kjellman, who adds certain details in his remarks. 

 The original host is Dilsea Integra (Kjellm.) Rosenv. {Sarcophyllis 

 arctica Kjellm.). The cells of the Chlorochytrium are placed, in most 



