80 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 12 



The brown oval cells characteristic of this genus have been interpreted 

 as "sporangia" and as "propagulae." Their walls are said to be thick. 

 However, when restored with KOH and studied, the outer wall in the 

 present material was not found to be particularly heavy. The contents 

 are figured by Bornet as alveolate, but older ones gave the appearance of 

 containing oval bodies 6.0-8.5 /* in greatest diameter. When the old 

 "sporangia" are crushed the contents appear to consist of a number of 

 separate, refractive brownish bodies, slightly angular-compressed by con- 

 tact. These Bornet (1890, p. 146) interprets as tannin masses. The 

 Galapagos Zosterocarpus plants differ from Z. Oedogonium Menegh. in 

 being more slender and having the brown "sporangia" considerably wider 

 than the diameter of the filaments which bear them, instead of being about 

 the same diameter. The contents of the vegetative cells in this material 

 shrank very much in drying, giving to the lesser branches a falsely beaded 

 appearance. 



Ecuador: Archpielago de Colon, an epiphyte dredged from 55 

 meters' depth o?i Post Office Bay, I. Santa Maria, no. 34-380 (TYPE), 

 29 Jan. 1934. 



Ralfsiaceae*'^ 



RALFSIA Berkeley, 1831 



Plants crustose, perennial, often one to several centimeters in diameter, 

 composed of radial filament systems laterally united to form a horizontal 

 layer, from which arise parallel series of cells to form a thick pseudoparen- 

 chymatous crust; unilocular sporangia and plurilocular gametangia in 

 sori on separate plants, the former lateral on free paraphyses, the lateral 

 terminal on the erect filaments. 



KEY TO SPECIES 



1. Thallus 2-4 cm diam., 280-350 ix thick; paraphyses cylindrical to 

 slightly clavate, 9-11 /x diam. at the end, 180-220 [l long; zoo- 

 sporangia clavate, 16-22 p., occasionally to 32 fi diam., 80-95, 

 occasionally to 140 /. long R. calif ornica 



1. Thallus to 4 cm diam., 450-750 fi thick; paraphyses 100-250 ii 

 long, the tip slightly swollen to 8-10 /x diam.; zoosporangia 40- 

 70 /x long, 18-30 II diam., gametangia 40-60 /x long, 6.0-8.0 /x 

 diam., each terminated by a single isodiametric cell R. occidentalis 



60 Identifications of Ralfsiaceae, and the accompanying notes, are supplied by 

 the kindness of Prof. G. J. Hollenberg. ^ j e> , <= u^pwcu uy 



