NO. 1 TAYLOR: PACIFIC MARINE ALGAE 261 



Ecuador: Archipielago de Colon, occasional on an exposed rock 

 with Gymnothamnion, Pta. Albemarle, I. Isabela, no. 34-120 p. p., (tet- 

 rasporic), 12 Jan. 1934. 



ANTITHAMNION Nageli, 1847 

 Plants tufted, of uncorticated uniseriate filaments; branches repeat- 

 edly opposite or whorled, sometimes one member of the pair suppressed, 

 or in the ultimate branching sometimes truly alternate ; refractive color- 

 less gland cells often present, appressed to the cells of the branchlet; 

 sporangia tetrapartite, carried on the smaller branchlets, or replacing 

 branchlets of the last order; spermatangia in patches of colorless con- 

 densed filaments on the branches of the last order; cystocarps formed on 

 the lowest cells of the vegetative branchlets, the upper portions of which 

 often do not develop fully. 



KEY TO SPECIES 

 1. Plants large, some centimeters in height, the terminal cells of the 



branchlets obtuse A. occidentale 



1. Plants small, the terminal cells of the branchlets acute A. veleroae 



Antithamnion occidentale Kylin 



Kylin 1925, p. 47, figs. 30a-d. 



The present specimens, although sterile, compare well with authentic 

 specimens of Kylin's collecting, and others from Puget Sound. They repre- 

 sent a rather lax and irregular form, but Kylin's specimens and his de- 

 scription show that there is considerable variation in the species. 



Ecuador: Archipielago de Colon, a major item as dredged from 36- 

 55 meters off a sandy bottom near an islet in Gardner Bay, I. Espanola, 

 no. 34-406, 31 Jan. 1934. 



Antithamnion veleroae n. sp.^^^ 

 Plants small, creeping below and attached by lobed disciform haptera 

 on short rhizoidal branches, the main filaments to 50-65 fi diam., and the 



162 Antithamnion veleroae n. sp. — Planta parva, infra repens; filamentis pri- 

 mariis ad 50-65 ^ diam., cellulis circa 100-150 [i long.; ramis erectis breyibus, 

 0.2-0.5, raro ad 1.5 cm altitudine, irregulariter ramosis; ramulis paululum incur- 

 vatis, paribus oppositis, cellulis 20 M' diam., circa 25-30 \i long., cellulis cacuminum 

 brevibus acutisque; glandicellulis in ramulis, tres cellulas vix contingentibus ; 

 tetrasporangiis sessilibus, 1-4 seriatis in latere superiore ramulorum ultimorum, 

 21-25 \i diam., 25-30 ja long.; cystocarpis ad cacumina ramorum erectorum formatis, 

 conicis, 150 n long., 75 M- diam. Planta typica in loco dicto I. Santa Maria, Ecuador, 

 legit W. R. Taylor no. 34-394B p. p., 30 Jan. 1934. 



