104 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 17 



The thick nemathecium with many-celled, catenate paraphyses, the 

 large sporangia and the multicellular rhizoids mark this species as a 

 distinctive member of the genus. 



Peyssonelia rubra var. orientalis Weber van Bosse 



Plate 10, figs. 8-9 



Weber van Bosse, 1921, p. 270-272, figs. 86-89. Peyssonelia rubra 

 (Grev.) J. Ag. as interpreted by Taylor, 1945, p. 168; Setchell & 

 Gardner, 1930, p. 175. 



Thalli forming crusts to 7-8 cm. broad on shells and rocks, lightly 

 calcified on lower side, with a slight to moderate marginal lobing, the 

 upper surface provided with longitudinal striations and sometimes with 

 faint concentric bands, closely but rather loosely attached to the sub- 

 strate mainly by numerous unicellular rhizoids, sometimes with the 

 margins in part free, occasionally becoming superimposed, deep rose red 

 in color, sometimes crimson when fresh, 100-300 fx thick; hypothallus 

 as seen from below usually of cells 25-40 /a by 12-16 /x in dimensions, in 

 tangential section these cells tending to be taller than broad and with 

 ventral walls usually uniformly rounded so as to give a "cobblestone" 

 effect to the lower surface; perithallus of unbranched, usually strictly 

 erect rows of usually 6-10 cells, the lower of these cells more or less 

 isodiametrical or taller than broad, the upper ones flattened and 11-16 /x 

 broad; tetrasporangial nemathecia superficial, elevated, 80-160 fi thick, 

 of dense, slender, slightly clavate, simple or once-branched paraphyses in 

 a gelatinous matrix; tetrasporangia ovate to elongate ovate, 70-110 /x 

 long, 25-55 /x wide ; sexual reproduction not observed. 



Type: Holotype not designated. Original material of several 

 collections deposited in the Rijksherbarium, Leiden, Netherlands . 



Type locality: None specifically designated. Seventeen Dutch 

 East Indian localities indicated, from intertidal to 120 meters depth. 



Mexican distribution: Pacific Baja Calif. — D. 8457b, 8413, 

 8312, Isla Guadalupe, Dec; Howell 928, Kellett Channel, off Isla 

 Cedros, Aug. 15, 1932. (Specimens are also at hand from dredgings in 

 depths of 30-50 meters in the Channel Islands region of southern Cali- 

 fornia.) Gulf of Calif.— D. 860, Isla Jorge, intertidal, Feb.; D. 6997, 

 Bahia Salinas, Isla Carmen, Mar. ; D. 7242, Bahia Agua Verde, Mar. ; 

 D. 7029, Bahia San Gabriel, Isla Espiritu Santo, intertidal, Mar. ; D. 

 6939b, San Lorenzo Channel, Mar.; D. 3245, Punta Palmilla, inter- 



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