NO. 1 TAYLOR: PACIFIC MARINE ALGAE 89 



1 cm in width below the first forking; branching dichotomous, often 

 unequal, at intervals of 3-11 cm, segments slightly tapered downward to 

 each forking, to about 8-10 mm broad in the lower part of the plant but 

 to 18 mm at a fork, 2-4 mm in the ultimate segments, in taller specimens 

 noticeably sinuous curved; angles below narrow, acute or slightly 

 rounded, in the upper portions 45°-60° and a little rounded, the branch 

 tips rounded; antheridial sori very abundant, readily visible with the 

 unaided eye; oogonial sori small, dark, also visible without a lens. 



This very large Dictyota is not so broad as D. dichotoma v. menstru- 

 alts Hoyt, and is taller and more erectly branched. However, there is a 

 good deal of similarity. It is somewhat similar to the New Zealand D. 

 ocellata J. Agardh, but is a lighter, less bushy thing with longer, less 

 tapering segments, as shown by comparison with material in the Agardh- 

 ian Herbarium at Lund. The curious sinuous deflexions in the plane of 

 the blade of older plants may be distinctive. 



Ecuador: Archipielago de Colon, rare as dredged from 13-18 meters 

 off Post OfHce Bay, I. Santa Maria, no. 34-357 (TYPE), 27 Jan. 1934. 

 Ibid. J dredged off a rocky bottom at 36-55 meters near an islet in Gardner 

 Bay, I. Espafiola, no. 34-423, 31 Jan. 1934. Ibid., dredged from 37 

 meters' depth off a rocky bottom, Schmitt no. 362C-35, 19 Dec. 1934. 



Dictyota Vivesii Howe 



Howe 1911, p. 497, pi. 27; Dawson 1944, p. 229. 



Mexico: Baja California, intertidal on Point Hughes, Cabo San 

 Lazaro, nos. 34-596, 34-597, 7 Mar. 1934. Is. Revilla Gigedo, dredged 

 from 22 meters' depth at sta. 970 off I. Maria Magdalena, no. 39-664, 9 

 May 1939. 



Dictyota concrescens n. sp.^^ 

 Plate 10, Fig. 2 



Plants small, crowded, light brown, delicate, to 3-4 cm tall, the blades 

 commonly becoming attached to each other, very irregularly dichoto- 

 mously branched, the segments short and relatively broad, tapering 



66 Dictyota concrescens n. sp. — Plantae frequentes, ad 3-4 cm altitudine, 

 plerumque inter se adhaerescentes ; irregularissime dichotome ramosae, segmentis 

 brevibus latisque, attingentibus ad 15 mm in fastigio segmentorum, longioribus, 

 autem, infra quam supra ubi rami confertissimi enascuntur atque subpalmati 

 videntur, segmentis terrainalibus 2-3 mm latitudine. Planta typica in loco dicto 

 Point Hughes, Cabo San Lazaro, Mexico, legit W. R. Taylor no. 24-598, 7 Mar. 

 1934. 



