NO. 1 TAYLOR: PACIFIC MARINE ALGAE 189 



Amphiroa mexicana n. sp.^^'' 

 Plate 47 



Plants closely tufted, to 3.0-4.5 cm tall, the branching closely dichot- 

 omous, with few lateral branches, the divisions erect or, in the upper- 

 most forkings, somewhat more spreading and more complanate ; segments 

 0.8-1.2 mm diam., or in the tips only about 0.6 mm, in length 1.5-3.2 mm, 

 generally 2-4 times as long as wide ; generally terete or very slightly com- 

 pressed, though more so below a fork, the segments bearing branches 

 truncate or often equally or unequally bifurcate, the flexible nodes fairly 

 evident; conceptacles numerous, equally distributed around the branches, 

 very slightly elevated, about 350 [i diam., the pore minute. 



These plants suggest J. peninsularis, but are smaller and more closely 

 branched, with relatively stouter, shorter segments. The medullary fila- 

 ments show alternating long and shorter segments. Perhaps the most 

 typical alternation is like that found in J. peninsularis, i.e., one transverse 

 series of quite small cells following four of long, but successively shorter, 

 cells. However, the zone of short cells was as often found succeeding 

 only one, two, or three zones of longer ones. 



Mexico: Guerrero, collected in some abundance along the shore 

 inside the Morro de Petatlan, Schmitt no. 120C-33 (TYPE), 17 Mar. 

 1933. 



Amphiroa galapagensis n. sp.^^^ 

 Plate 51, Figs. 1-5 



Plants turflike, to 4 cm tall, without recognizable basal crust, fairly 

 regularly dichotomously branched, the branches erect, rather broader 

 above; segments rose pink, the flexible joints distinct, blackish; segments 

 in the lower portion of the plants subterete, those in the central and upper 

 portions distinctly compressed, especially in the uppermost parts, the 

 margins parallel or subcuneate, the upper angles somewhat truncate, 



110 Amphiroa mexicana n. sp. — Plantae caespitosae, ad 4.5 mm altitudine, arete 

 dichotome ramosae, segmentis infra 0.8-1.2 mm diam., in cacuminibus 0.6 mm, 

 plerumque 2-4 plo longioribus quam latis, teretibus praeterquam quod, praecipue 

 infra furcam, subcompressa sunt, ramum ferentibus, saepe bifurcatis; conceptacu- 

 lis radiatim dispositis, paulum elevatis, 350 n diam. Pianta typica in loco dicto 

 Ba. Petatlan, Mexico, coll. W. L. Schmitt no. 120C-33, 17 Mar. 1933. 



111 Amphiroa galapagensis n. sp. — Plantae caespitideae, ad 5 cm altitudine, 

 axibus erectis, dichotome ramosis, articulis fiexibilibus distinctis, fuscis ; segmentis 

 calcifactis infra subteretibus, 0.8-1.0 mm diam., supra distincte compressis, ad 1.0- 

 1.5 mm latitudine, crassitudine circa 0.25 magnitudinis. Pianta typica in loco dicto 

 I. Santa Maria, Ecuador, legit W. R. Taylor no. 34-235, 17 Jan. 1934. 



