NO. 1 TAYLOR: PACIFIC MARINE ALGAE 49 



KEY TO SPECIES 



1. Thallus larger ; cells without intracellular spines . . D. australis 

 1. Thallus very small; cells with intracellular spines . D. Versluysi 



Dictyosphaeria australis Setchell 



Plants 1.0-4.5 cm or more in diameter, flattened or cushion shaped, 

 irregular or lobed, light green, iridescent; solid at all stages seen, attached 

 firmly by groups of rhizoidal cells, the surface cells veiy irregular in size, 

 reaching 1-2 mm, the outer face moderately curved ; intercellular hapteres 

 mostly along the angles of junction, seldom on the cell surfaces ; needle- 

 shaped projections (intracellular spines) apparently absent from the cell 

 walls. 



Setchell 1926, p. 79, pi. 8, figs. 9, 10. 



These specimens suggest D. intermedia Weber-van Bosse (1905, p. 

 143), but were not seen to become hollow and had rather larger cells. 

 Setchell describes D. australis from Tahiti as having very scattered and 

 very rare intracellular spines, but these were not seen in this material at 

 all, leaving the identity slightly in doubt. Plants of the intertidal zone 

 and in tide pools, generally in fairly exposed situations. 



Mexico: Is. Revilla Gigedo, drifted ashore at Sulphur Bay, I. 

 Clarion, no. 34-55, 5 Jan. 1934. Ibid., common in the upper intertidal 

 zone wedged between rocks and attached along rock crevices, no. 39-13, 

 16 Mar. 1939. Ibid., on rocks in tide pools along the shore, Braithwaite 

 Bay, I. Soccoro, no. 34-26, 3 Jan. 1934, and no. 39-54, 18 Mar. 1939. 



Dictyosphaeria Versluysi Weber-van Bosse 



Thallus small, solid, the cells 0.5-1.5 mm diam., with intracellular 

 spines evident. 



Weber-van Bosse 1905, p. 114; Setchell & Gardner 1930, p. 115. 



This plant, which Mme. Weber-van Bosse described from the Malay 

 reefs, appears here as a plant of intertidal and tide-pool rocks. 



Mexico: Is. Revilla Gigedo, occasional in tide pools, Braithwaite 

 Bay, I. Soccoro, no. 34-8, 2 Jan. 1934. 



BOODLEA Murray & DeToni, 1889 



Plants entangled, often to form a spongy mass; the main axes visible 

 below, less distinct above, branched, the patent branches opposite or 

 whorled, commonly adherent at the tips with tenacular attaching cells. 



