NO. 1 TAYLOR: PACIFIC MARINE ALGAE 119 



tendency for acute serration of the leaves, even above, and by the blunt 

 leaf tips. The leaves resemble considerably those of the Caribbean S. 

 cymosum, but are in general larger and the receptacles are more congested. 

 In common with many other Sargassa a compact form seems also to exist 

 (no. 34-350C). 



Ecuador: Archipielago de Colon, drifted ashore on Pta. Albemarle, 

 I. Isabela, no. 34-105 (TYPE), 12 Jan. 1934. Ibid., drifted ashore in 

 Tagus Cove, no. 34-149 F, 13 Jan. 1934. Ibid., on reef north of the 

 cove, no. 34-173B, 13 Jan. 1934. Ibid., on rocks near low tide line, no. 

 34-145, 13 Jan. 1934. Ibid., rare as drifted onto the shore of I. Bartol- 

 ome, I. San Salvador, no. 34-350C, 23 Jan. 1934. 



Sargassum Howellil Setchell 

 Plate 28 



Setchell 1937b, p. 132, pi. 28, figs. 7-10, pi. 31, fig. 49. 



These plants in most respects fit the type description. However, the 

 leaves are rather more definitely and closely serrate in most instances and 

 particularly in the leaves of the basal tuft, and the cryptostomata are 

 more distinct, and, though scattered more, tending to be concentrated in 

 a row along each side of the midrib. Examination of the type material 

 kindly loaned by the California Academy of Sciences revealed that upper 

 and younger leaves were distinctly and moderately serrate. The large 

 leaves became oblong lanceolate and reached 65 mm in length, 8 mm in 

 width, though the smaller ones were more truly lanceolate. Setchell's fig. 

 10 on pi. 28 is characteristic of the old and worn leaves, but entirely 

 unlike the upper undamaged ones. The serrations occur at intervals of 

 about 0.75-2.0 mm, are acute and about 0.3-1.0 mm long. The type speci- 

 mens appear to be old and considerably condensed, perhaps by growing 

 in an exposed place, and rather waterworn. This last feature tends to 

 obscure the cryptostomata. It is curious that no Sargassa were found on 

 either trip at Clarion I., the type locality for this species, though the 1939 

 visit was in March, the same month in which the type had been collected 

 7 years before. 



Mexico: Is. Revilla Gigedo, frequent in the littoral, as in the surf, 

 on rocks in gullies near low tide line, Braithwaite Bay, I. Soccoro, nos. 

 34-11, 34-24A, 2, 3 Jan. 1934, and no. 39-50, 18 Mar. 1939. 



Sargassum Liebtnannii J. Agardh 

 Plate 29 



Agardh, J. G. 1847, p. 8; 1889, p. 91, pi. 5, figs. 1-3; Kiitzing 1861, 

 pi. 41 (as Carpacanthus Liebmannii) ; Setchell 1937b, p. 130, pi. 28, figs. 

 1-3. 



