NO. 1 TAYLOR: PACIFIC MARINE ALGAE 225 



produced from surface cells of the male plants over large areas of the 

 thallus; cystocarps prominent, to 1-2 mm diam., marginal in young plants 

 or in proliferations, later facial, but in the small marginal branchlets 

 cystocarps, the outer tissue about the spores parenchymatous, of oval cells, 

 the inner layers filamentous, the spore mass with a center of colorless 

 sterile cells which may break down in old, large cystocarps, surrounded 

 by the carpospores and anchored to the surrounding tissue by trabeculae. 



This plant seems rather closely related to S. furcata (Setchell & 

 Gardner) Kylin (1932, p. 16), but is a smaller species with pinnate sec- 

 ondary branching and a tendency for aggregation of the cj'Stocarps, chiefly 

 in the secondaiy branches. The Pta. Cristofer specimen is rather peculiar 

 and is included tentatively as a piece past maturity. It consists of a frag- 

 ment of one fork about 14 cm long and 3 cm wide below, with one forked 

 proliferation 8 cm long. The material is tetrasporic. Over the face there 

 are many small plantlets, from mere granules up to some a centimeter in 

 length. Around the margin are a few larger ones, indeed one over 2 cm 

 long, and a few of these are marginally cystocarpic, and others are sperma- 

 tangial. They probably arose from germinated tetraspores. This fragment 

 may indicate that the species can attain considerably larger size than is 

 ascribed to it. 



Mexico: Nayarit, dredged from 21.5 meters' depth at sta. 970 near 

 I. Maria Magdalena, Las Tres Marias, no. 39-651, 9 May 1939. Costa 

 Rica: dredged off Pto. Culebra, no. 34-527B (cystocarpic), 24 Feb. 

 1934. Ecuador: Archipielago de Colon, dredged in 27-55 meters off 

 Tagus Cove, I. Isabela, no. 34-135 (cystocarpic), 13 Jan. 1934. Ibid., 

 dredged from 18-32 meters at sta. 157, no. 34-188 (tetrasporic), 15 Jan. 

 1934. Ibid., drifting off Pt. Christopher, no. 34-199 (proliferous), 16 

 Jan. 1934. Ibid., dredged from 36 meters' depth opposite Gordon Rocks, 

 I. Santa Cruz, Schmitt no. 316F-34 (cystocarpic), 8 Dec. 1934. Ibid., 

 dredged from 13-18 meters' depth off Post Office Bay, I. Santa Maria, 

 no. 34-359 (cystocarpic and tetrasporic, TYPE), 29 Jan. 1934. Ibid., 

 dredged in 27 meters, no. 34-27 6A (tetrasporic), 19 Jan. 1934. Ibid., 

 dredged in 9 meters, I. Baltra, no. 34-333 (cystocarpic), 22 Jan. 1934. 



Rhabdoniaceae 



Thallus cylindrical or flattened, radially or bilaterally branched; 

 apical growth with a central filament which commonly becomes obscure; 

 medulla filamentous, the cortex of close, somewhat obscurely radial rows 

 of cells, the inner large, the outer progressively smaller ; tetrasporangia 

 zonate, scattered in the cortex ; cystocarps immersed, without special peri- 

 carp tissue, the carpospores radiating from a large fusion cell, dischargmg 

 through a pore. 



