NO. 1 TAYLOR: PACIFIC MARINE ALGAE 167 



561, 28 Feb. 1934. Costa Rica: abundant on shalelike rock, Port 

 Parker, no. 39-84, 25 Mar. 1939. Panama: on rocks exposed to severe 

 surges, Is. Secas, no. 39-120, 26 IVIar. 1939. Ibid., on rocks, San Fran- 

 cisco, Panama City, no. 39-147, 31 Mar. 1939. Colombia: Valle, on 

 littoral rocks, I. Gorgona, no. 34-495E, 12 Feb. 1934. Ecuador: Ar- 

 chipielago de Colon, on intertidal rocks, I. Wenman, no. 34-93 (p.p.), 11 

 Jan. 1934. Ibid., on lava in a brackish lagoon, Pta. Albemarle, I. Isa- 

 bela, no. 34-95 A, 12 Jan. 1934. Ibid., intertidal on rocks, Ba. Cartago, 

 I. Isabela, no. 34-352 C, 25 Jan. 1934. Ibid., abundant on water-worn 

 lava rock fragments in tide pools, I. Baltra, no. 34-328, 22 Jan. 1934. 

 Ibid., on intertidal rocks on an islet in Gardner Bay, I. Espaiiola, no. 34- 

 430,Z\}^n.\9ZA. 



Hildenbrandia occidentalis Setchell 



Setchell in Gardner 1917, p. 393, pi. 33, fig. 4; Smith 1944, p. 215, 

 pi. 49, fig. 4. 



Ecuador: Archipielago de Colon, on intertidal rocks, I. Wenman, 

 no. 34-93 (p.p.), 11 Jan. 1934. 



PEYSSONNELIA Decaisne, 1841 



Plants crustose or subcrustose, little to considerably calcified, forming 

 expansions over the substratum or marginally free, attached by the entire 

 surface of the lower layer or by rhizoids; basal layer of radiating fila- 

 ments, simple or dichotomously branched, forming parallel rows, the 

 upper or perithallus layer of ascending to erect filaments borne upon these ; 

 erect filaments simple or sparingly dichotomously branched, closely later- 

 ally united ; reproductive organs in nemathecia of unconsolidated fila- 

 ments or of specialized paraphyses on the upper surface ; sporangia tetra- 

 partite, associated with paraphyses; spermatangia lateral on the free fila- 

 ments; carpogenic branches four or five celled, lateral on the bases of the 

 free filaments, after fertilization uniting by ooblast filaments with auxili- 

 ary cells formed by other filaments, and there producing scattered gonimo- 

 blasts of eight to twelve large carposporangia. 



KEY TO SPECIES 



1. Thallus lightly calcified, chiefly below; thin and relatively lightly 

 attached to the substratum P. rubra 



1. Thallus considerably calcified; much thicker and more firmly 

 attached to the substratum 2 



