56 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 12 



Rhizoclonium lubricum Setchell & Gardner 



Setchell & Gardner 1920, p. 185, pi. 9, figs. 5a, 5b. 



Costa Rica: Pto. Culebra, in tide pools, no. 34-534, 24 Feb. 1934. 



CLADOPHORA Kiitzing, 1843 



Plants bushy, at least at first basally attached, freely alternately or 

 oppositely branched, filamentous, uniseriate, the cells multinucleate, with 

 little difference between axial and branch cells ; growth apical. 



KEY TO SPECIES 



1. Plants matted, or loose in tide pools 3 



1. Plants tufted 2 



2. Plants small, densely tufted ; dark green, drying brownish ; axis 

 cells to 300 II diam C. prolifera 



2. Plants larger, softly bushy; remaining green upon drying; the 

 axis cells not exceeding about 130 /a diam C. sp. 



3. Plants lax, early detached, irregularly branched, the main axes 



to about 150 ju, diam C. gracilis f. expansa 



3. Plants forming spongy cushions or mats, the main axes to 77 /* 



diam C. panamensis 



Other specimens of Cladophora were collected on these expeditions, 

 but it is felt that the specimens are not in sufficiently well-developed con- 

 dition to make identification, or even description, possible. However, the 

 genus was not particularly common at the stations visited. 



Cladophora panamensis n, sp.'*'^ 



Plants forming spongy dull-green cushions or mats 1-2 cm thick; fila- 

 ments intricately entangled without special distinction of creeping axes; 

 main axes indefinite, to 77 /x diam., the cells 2.5-4.0 diameters long, 

 branching di-trichotomously, or somewhat irregularly, the branches often 

 slightly connate at the base, often with small lateral branches which may 

 divide or be subsimple and often rhizoidal; upper branching very irregii- 



47 Cladophora panamensis n. sp. — Planta spongiosa, obscure viridis, 1-2 cm 

 crassis; filamentis non repentibus, ad 77 \i diam.; cellulis 2.5-4.0 plo diam. longi- 

 tudine; infra ramificatione dichotoma ad trichotomam, supra dichotoma ad opposi- 

 tam; ramusculis ad circa 30 n diam., cellulis 3-5 plo diam. longitudine, cacumini- 

 bus obtusis. Planta typica in loco dicto Bahia Honda, Panamd, legit W. R. Taylor, 

 no. 39-131. 26 Mar. 1939. 



