NO. 1 TAYLOR: PACIFIC MARINE ALGAE 81 



Ralfsia califomica Setchell & Gardner, prox. 



Setchell & Gardner 1925, p. 497, pi. 36, fig. 22. 

 Mexico : Jalisco, on hard intertidal rocks at Ba. Tenacatita, no. 34- 

 565, 2 Mar. 1934. 



Ralfsia occidentalis G. J. Hollenberg, n. sp.^^^ 



Plants forming dark brown crusts on rocks, 450-750 /a thick and to 4 

 cm or more in diameter, seemingly without evident radial or circumfer- 

 ential growth ridges, firmly attached to the substrate; hypothallus com- 

 posed of rows of horizontally elongate cells 15-19 /a diam., and mostly 

 1.5-2.0 diameters long, some of the cell rows curving toward the sub- 

 strate, but mostly curving upward and merging abruptly with the erect 

 photosynthetic filaments of the perithallus ; perithallus 70-90 /n thick, 

 composed of filaments whose cells are 4.0-6.0 p. diam., 1.0-1.5 diameters 

 long and mostly not arranged in distinct periclinal layers; plurangia 

 ('plurilocular gametangia') 40-60 /a long and 6.0-8.0 /t diam., each 

 terminated by a single isodiametric sterile cell ; unilocular sporangia 40- 

 70 /A long, 18-30 jjL diam., among paraphyses 100-250 ix long and 8-10 

 jjL diam. at the slightly swollen tip, composed of about 15 cells mostly 

 longer than wide; hair pits infrequent. 



In many respects Ralfsia occidentalis is similar to R. verrucosa 

 (Aresch.) J. Agardh common in the north Atlantic, but differs from the 

 latter chiefly in the lack of horizontal stratification so common to the 

 Atlantic plant. If one may judge by the somewhat fragmentary material 

 available, R. occidentalis seems to be more firmly attached to the sub- 

 strate. A species of Ralfsia common along the coast of southern California, 

 which has passed for R. verrucosa, is likewise similar to R. occidentalis, 

 but the Californian plant has a hypothallus composed almost exclusively 



61 Ralfsia occidentalis G. J. Hollenberg n. sp. — Plantae in saxis crustas atro- 

 bruneas formantes, 450-750 \i. crass., ad 4 cm. aut plus diam., sine perspicuis 

 incrementi rugis radialibus aut circumferentialibus, ad substratum firme affixas; 

 hypothallo coraposito ex ordinibus cellularum horizontaliter elongatarum, 15-19 \i 

 diam., maxima ex parte 1.5-2.0 plo diam. longitudine, quibusdam ex ordinibus 

 cellularum ad substratum curvatis, plurimis, autem, sursura curvatis et cum fila- 

 mentis perithalli erectis photosyntheticis abrupte commixtis; perithallo 70-90 n 

 crass., coraposito e filamentis quorum cellulae diametron 4.0-6.0 \i, longitudinera 

 1.0-1.5 plo diam. habent et maxima ex parte in stratis periclinalibus distinctis non 

 ordinatae sunt; plurangiis (gametangiis plurilocularibus) 40-60 \i long., 6.0-8.0 

 \i diam., omnibus per singulam cellulam isodiametricam, sterilem terminatis; spor- 

 angiis unilocularibus 40-70 |.i long., 18-30 ^.diam., inter paraphyses 100-250 \i long, 

 et, ad apicem subinflatum, 8-10 \i diam., corapositas e circa 15 cellulis maxima ex 

 parte longioribus quam latis ; lacunis pilorum raris. 



Planta typica in loco dicto Braithwaite Bay, I. Soccoro, Mexico, legit W. R. 

 Taylor no. 34-31, 2 Jan. 1934. 



