NO. 1 TAYLOR: PACIFIC MARINE ALGAE 85 



quence less tough ; the gametangia seem to be much shorter. The illustra- 

 tion is made from a very small specimen held in fluid, for the larger 

 clumps after pressing gave a poor idea of their habit. 



Mexico: Baja California, in littoral pools at South Bay, I. Cerros, 

 no. 34-651 (TYPE), 10 Mar. 1934. Costa Rica: Ba. Salinas, from 

 shallow water along shore, Schmitt no. 474A-35, 10 Feb. 1935. Ibid., 

 occasional tufts on rocks in crevices near low tide line. Port Parker, no, 

 39-76, 25 Mar. 1939. 



Colpomenia mollis n. sp.^^ 



Plant to 1.0-1.5 cm tall, soft, and delicate, a little compressed, hollow, 

 sparingly irregularly divided to short branches 2-3 mm diam., a little 

 shorter or longer than broad, their ends rounded truncate and in some 

 bearing short spinelike projections; structurally showing a wall of about 

 two cells in thickness, the cortical cells in surface view 8.5-15.0 /u, diam., 

 subquadrangular, rather irregularly arranged; colorless medullary cells 

 probably only in one layer, the cells angular, 40-85 ft diam., the walls 

 very thin. 



This small and delicate species was secured only in very small 

 quantity, and it did not revive enough when sectioned to enable measure- 

 ments of the wall thickness to be secured. It is probably much thinner 

 than ordinary in this genus. 



Colombia: Valle, scarce on rocks in littoral pools on I. Gorgona, 

 no. 34-491A (TYPE), 12 Feb. 1934. 



Sphacelariaceae 



Plants erect from a holdfast, or the basal branches rhizomatous; 

 usually polysiphonous, growing by segmentation of a large apical cell; 

 sometimes corticated by rhizoids ; branches similar to the axis, or in other 

 cases the axis and its main divisions clothed with short branchlets; uni- 

 locular sporangia and plurilocular gametangia on branchlets derived from 

 the vegetative axis or from the cortex, the sexual and asexual plants 

 similar in appearance. 



63 Colpomenia mollis n. sp. — Planta ad 1.5 cm altitudine, mollissima, paulum 

 compressa, sparse irregulariterque divisa in ramos 2-3 mm diam., partibus termin- 

 alibus rotundato-truncatis ; membrana tenuissima, fortasse e solis duobus cellu- 

 larum stratis constante. Planta typica in loco dicto I. Gorgona, Colombia, legit W. 

 R. Taylor no. 34-491A, 12 Feb. 1934. 



