NO. 1 TAYLOR: PACIFIC MARINE ALGAE 251 



Rhodymenia divaricata Dawson 



Dawson 1941, p. 141, pi. 23, fig. 31. 



This material corresponds closely to Dawson's illustration, but is, like 

 his, sterile and adds nothing to his diagnosis. It is quite possibly a small, 

 narrow form of R. calif ornica Kylin. 



Ecuador: Archipielago de Colon, dredged from 27 meters off Post 

 Office Bay, I. Santa Maria, no. 34-282, 19 Jan. 1934. 



Rhodymenia decumbens n. sp.^^* 

 Plate 84, Fig. 1 



Plants decumbent, very brittle, fleshy but thin, when dry dull reddish- 

 and dull of surface, with no evident stalk, the more or less interlaced 

 branches forking dichotomously, the angles wide, between 80° and 110°, 

 the sinuses slightly rounded, 5-25 mm between the forkings, the segments 

 strap shaped, 1.5-2.0 mm broad, the apices obtuse; reproduction unknown. 



This plant somewhat suggests R. divaricata Dawson, but is a much 

 bigger thing, forming rather extensive mats. Without fruit the generic 

 assignment is not assured. 



Ecuador: Archipielago de Colon, dredged off shore in 9 meters of 

 water, I. Baltra, no. 34-331 (TYPE), 22 Jan. 1934. 



Rhodymenia Dawsonii n. sp.^^^' ^^ 

 Plate 84, Fig. 2 



Plants to 2 dm tall, gregarious, bushy, firm in texture, dull red in 

 color and when dry dull or a little glaucous; fairly regularly dichot- 

 omously branched 7-10 times, near the base the axes compressed, about 1 

 mm diam., but above quite flat, the lower segments to 2-3 mm in width, 

 the upper ones 0.75-1.0 mm, the terminal segments somewhat tapered, 

 rounded acute at the tips; structurally showing a medulla of moderately 



154 Rhodymenia decumbens n. sp. — Planta decumbens, fragilis, tenuis, sine 

 stipite perspicua, ramis in angulis 80°-110° dichotome divisis, implectis, segmentis 

 ligulatis, 1.5-2.0 mm latitudine, cacuminibus obtusis. Planta typica in loco dicto I. 

 Baltra, Ecuador, legit W. R. Taylor no. 34-331, 22 Jan. 1934. 



155 Rhodymenia Dawsonii n. sp. — Plantae ad 2 dm altitudine, fruticosae, tex- 

 tura firmae, axe ad basim compresso, ramis supra planis, 7-10 dichotome divisis, 

 segmentis infra 2-3 mm lat., supra 0.75-1.0 mm lat., cacuminibus rotundato-acutis; 

 tetrasporangiis in soris 1-2 mm diam. ad cacumina segmentorum obtusorum; cysto- 

 carpis marginalibus aut submarginalibus in segmentis superioribus tenuibus promi- 

 nentibusque, ad 1.0-1.25 mm diam. Planta typica in loco dicto Cabo San Lazaro, 

 Baja California, Mexico, legit W. R. Taylor no. 34-602, 7 Mar. 1934. 



156 Named in recognition of the studies of this genus made by Dr. E. Yale 

 Dawson. 



