1920] SetcJiell-Gardner : ChloropJiyceae 151 



3. Codiolum A. Brann 



Frond unicellular, ovoid to clavate or subcylindrical, the cell wall 

 prolonged below into a longer or shorter stipe, attached by a simple 

 or forked expansion ; chromatophore covering the cell wall or more 

 or less broken, with several pyrenoids ; asexual reproduction by 4- 

 ciliated zoospores, many in a cell. 



A. Braun, Algarum Unic, 1855, p. 19. 



This genus was first mentioned in 1852 by Braun before the 29th 

 Congress of naturalists and physicians at Wiesbaden (cf. Flora, 1852, 

 p. 755) and was excellently described and illustrated in full in 

 1855 in his "Algarum Unicellularum Genera nova et minus cognita" 

 (p. 19). The type species is Codiolum gregarium A. Braun, and the 

 type locality is Helgoland. 



The species of Codiolum are all very similar and consist of a color- 

 less stipe of longer or shorter dimensions bearing above a swollen cell 

 which is elongated ovoid in shape and which is termed the "clava." 

 The dimensions of both stipe and clava differ somewhat even in the 

 same species, but in the endophytic species the stipe may be abbre- 

 viated or even, most commonly, wanting. 



Key to the Species 



1. Cells with a long stipe not endophytic 1. C. gregarium (p. 151) 



1. Cells with stipe short or wanting, endophytic 2. C. Petrocelidis (p. 152) 



1. Codiolum gregarium A. Braun 

 Plate 15, fig. 2 



Clava narrowly elliptical in median section, definitely delimited 

 from the long narrow stipe, up to 500/^ long, and lOO^u, wide ; stipe 

 hyaline, unbranched, nearly cylindrical but slightly enlarging upward, 

 600-1000/x long, 20-30ju, wide, somewhat disk-shaped at the base. 



Reported from a single locality in our region, growing on an iron 

 buoy near Friday Harbor, San Juan Count}^ Washington. 



A. Braun, Alg. Unic, 1855, p. 20, pi. I, f. 1-17 ; Collins, Green Alg. 

 N. A., 1909, p. 152. 



There have been described several species of Codiolum beside the 

 endophj^tic species and these species have been dependent largely upon 

 differences in various dimensions, but particularly on length of stipe. 

 Borgesen, however, in his "Marine Algae of the Faeroes" (1902, 



