160 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 12 



pinnately branched, the outer divisions somewhat triangular, complanate, 

 the axis evident to the tip; main axes to 1.0-1.2 mm wide, somewHat com- 

 pressed; lateral short branches naked at their bases, above pinnately 

 branched, the branchlets 0.2-0.5 mm diam., slightly compressed, tapering 

 slightly from near the rather obtuse apex to the base ; in transverse section 

 showing in the younger parts a few rhizines near the angles in the medul- 

 lary area, and in the older stems many, chiefly central; tetrasporangia in 

 branchlets very little different from the vegetative except that they are a 

 little more compressed, the fertile parts linear, the sorus occupying about 

 two thirds of the width of the branchlet, the spores in many vaguely 

 decussate rows, formed progressively with the growth of the slightly 

 indented apex and discharging in the older regions individually, without 

 producing a macroscopic perforation of the sorus area. 



These plants are fleshy rather than wiry, but yet very firm, contrasting 

 with P. Okamurai and P. robusta, where the branches are much flatter 

 and thinner. 



Mexico: Baja California, dredged off Point Hughes on Cabo San 

 Lazaro, no. 34-601 (tetrasporic, TYPE), 7 Mar. 1934. 



Pterocladia robusta n. sp.^^ 

 Plate 36 



Plant to 15 cm tall, rather fragile, dull red, except near the base flat 

 throughout, the lower main axes becoming naked, above regularly pin- 

 nately 2-4 times branched, the branches strongly contracted at the base, 

 the stronger axes thin, to 1.5-2.5 mm broad, the apices obtusely rounded, 

 particularly in the ligulate to spatulate branchlets. 



These plants somewhat resemble P. tenuis Okamura (1934, p. 62), 

 but are perhaps coarser and more divided, with less tendency for the ulti- 

 mate branchlets to be elongate. They are coarser and less abundantly 

 branched than P. Okamurai, but no doubt closely related to it. 



Ecuador : Archipielago de Colon, floating offshore at Pt. Christopher, 

 I. Isabela, no. 34-198 (TYPE), 16 Jan. 1934. Ibid., a few pieces 

 dredged from 27 meters off Post OflSce Bay, I. Santa Maria, no. 34-272, 

 19 Jan. 1934. 



96 Pterocladia robusta n. sp.— Plantae ad 15 cm altitudine, paululum fragiles, 

 planae, nisi ad basim, axibus infra nudis, supra regulariter 2-4-pinnate ramosis, 

 ramis in basi contractis, tenuibus, 1.5-2.5 mm latitudine, ramulis ligulatis ad 

 spatulatos, cacumina obtuse rotundata habentibus. Planta tj'pica in loco dicto 

 Pt. Christopher, I. Isabela, Ecuador, legit W. R. Taylor no. 34-198, 16 Jan. 1934. 



