NO. 1 DAWSON : MARINE RED ALGAE OF PACIFIC MEXICO 41 



Type locality: Ceylon. 



Mexican distribution: Pacific Baja Calif. — D. 10019, 10 miles 

 west of Punta Malanimo, Bahia Vizcaino, April. 



The Mexican plants at hand agree closely with the illustrations 

 given by Yamada (1938) for L. for7nosana, a name which he later re- 

 duced under L. orientalis. The 3-celled carpogonial branches are distinc- 

 tive as are the cystocarps with their compact gonimoblast and short, 

 coarse involucral filaments. 



The plant was found growing in very warm tide pools with Liagora 

 ceranoides var. leprosa on an exposed rocky shore subject to sustained 

 high surface water temperatures throughout the year. In view of the 

 apparent absence of other habitats of this sort on the Pacific Baja Cali- 

 fornia coast and the tropical nature of these species, the Bahia Vizcaino 

 plants are probably representative of a very restricted colony. 



Liagora abbottae sp. nov. 

 Plate 2, figs. 6-8; Plate IS, fig. 2 



Thallis ad 40 cm. altis, baud calcificatis, mollibus, lubricis, circa 2 

 mm. diametro, decrescentibus ad 1 mm. in ramulis ultimis, irregulariter 

 alternate multif arieque ramosis, ramulis ultimis paxilloformibus ; fila- 

 mentis assimilativis e cellulis ovatis vel breviclavatis in seriebus ramosis, 

 catenatis, 7-10 cellularum singulis; gonimoblasto e cellula terminali rami 

 carpogonialis, quinquevel etiam sexicellularis oriente, cellulis inferioribus 

 amplificatis, gonimoblastum attollentibus super rosulam involucralem 

 filamentorum vegetativorum e cellula lateralis vegetative ramum carpo- 

 gonialem subtendentis productorum. 



Thallis to 40 cm. high, lightly calcified, at least in part, soft, lubric- 

 ous, saxicolous, from a small, discoid holdfast which gives rise to several 

 erect, branched axes ; erect axes cylindrical, about 2 mm. in diameter in 

 main parts, decreasing to 1 mm. or less in ultimate branchlets, irregular- 

 ly alternately, multifariously branched at intervals of 3-20 mm., the 

 branches in turn branched in two orders, the ultimate fertile branchlets 

 being small peg-like papillae densely assembled on the lateral branchlets ; 

 thallus composed of a central loose axial tissue of branched, interlaced 

 filaments from which the radically arranged, chromatophore-bearing, 

 irregularly to dichotomously branched assimilatory filaments arise; 

 chromatophores discoid, parietal; assimilatory filaments consisting of 

 ovate or short-clavate cells arranged in branched, catenate series of 7-10 

 cells, sometimes tipped with a hair; base of the assimilatory filaments 



