158 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 12 



may belong to the present species. They have the very marked excurrent 

 main axis, without large lateral branches, which is very different from 

 the spreading G. serrulatum of Caribbean waters. 



Ecuador: Archipielago de Colon, occasional on rocks in the littoral 

 near Black Beach Anchorage, I. Santa Maria, no. 34-218B (tetrasporic, 

 TYPE), no. 34-215 (tetrasporic), 17 Jan. 1934. 



Gelidium filicinum Bory 



Bory 1828, p. 162; Farlow 1902, pp. 95, 96. 



The specimens being fragmentary, this determination should be 

 regarded with some caution, but comparison with Peruvian specimens of 

 G. filicinum and Trinidadian specimens of G. serrulatum J. Ag., both of 

 which Farlow reported from the Galapagos, indicates that these frag- 

 ments probably belong to G. filicinum, as do likewise the specimens from 

 I. Isabela in the Stanford University herbarium, on which Farlow based 

 his record. The specimens he called G. serrulatum from I. Wenman have 

 few main lateral branches and broader midribs. Howe (1914, p. 97) also 

 reported G. filicinum in turtle stomachs, though with some doubt. 



Ecuador: Archipielago de Colon, fragments in abundance taken 

 from the stomach of a marine turtle secured in an inland salt-water pool 

 which was apparently devoid of vegetation, but probably had an under- 

 water communication with the sea, I. Fernandina, no. 34-157 (tetra- 

 sporic), 14 Jan. 1934. 



PTEROCLADIA J. Agardh, 1852 



Small plants, to plants of moderate size, generally considerably 

 branched, slender and firm; structurally generally showing rhizines in 

 the central part of the medulla but none, or fewer, in the subcortex; 

 tetrasporangia in sori, formed progressively from near the apex, generally 

 in rows; cystocarps with a single loculus, discharging from a pore on one 

 $ide of the fertile branchlet. 



KEY TO SPECIES 



1. Plants turflike, small, about 1 cm tall .... P. musciformis 



1. Plants tufted, much taller 2 



2. Branches flat, almost membranous 3 



2. Branches compressed, but rather thick and firm . . P. mexicana 



3. Branchlets relatively slender, main axes to 1.5 mm wide; bushy, 

 closely branched plants P. Okamurai 



3. Branchlets broadly obtuse, main axes to 2.5 mm wide; rather 

 more sparingly branched plants P. robusta 



