NO. 1 TAYLOR: PACIFIC MARINE ALGAE 51 



convinced the writer that it was merely a variant of that species. It is 

 here described and recorded separately in order to call attention to its 

 peculiarities. 



Ecuador: Guayas, closely tufted and entangled with other algae, 

 especially Centroceras, on the rocky southeast side of Pta. St. Elena, 

 Salinas, no. 34-466, 8 Feb. 1934. 



GLADOPHOROPSIS B0rgesen, 1905 

 Cladophoropsis robusta Setchell & Gardner 



Plants to 2.5 cm tall, the base sparingly branched and rhizoidal, the 

 erect axes simple or 1-2 times successively oppositely branched, the lateral 

 branches usually without crosswalls until after one has been formed 

 across the axis above the fork; filaments below to 685 ju, diam., the cells 

 of irregular length, in the lower portions quite long. 



Setchell k Gardner 1924, p. 714, pi. 13, fig. 16. 



This material, very scanty, was shorter and more slender than the 

 maxima described by Setchell and Gardner. It generally formed branches 

 of one degree, often opposite, but often only single. One specimen formed 

 three pairs of branches on the main axis and the lower two pairs each 

 bore a pair of opposite branchlets in turn. This looks rather unlike the 

 figures given in the above publication, but the simpler plants resemble 

 the illustration very closely. 



Mexico: Nayarit, rare on the rocks of I. Isabel, no. 34-588A, 5 

 Mar. 1934. 



Cladophoraceae 



Plants filamentous, usually with distinct basal holdfasts, simple or 

 branched above, the branches rarely whorled, the filaments uniseriate; 

 cells with a commonly multinucleate protoplast; septation not notably 

 delayed ; reproduction by biflagellate zoospores or gametes from little- 

 differentiated cells. 



KEY TO GENERA 



1. Filaments unbranched, or with few short simple branchlets 2 



1. Filaments progressively, often abundantly, branched ... 3 



2. Filaments unbranched, symmetrical, often attached by a differ- 

 entiated basal cell Chaetomorpha 



2. Filaments more slender and irregular of contour; unbranched or 



with a few rhizoidal or lateral spur branches . . Rhizoclonium 



