64 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 12 



Mexico: Oaxaca, near the low tide mark in Ba. Tangola-Tangola, 

 no. 34-552 J 28 Feb. 1934. Ecuador: Archipielago de Colon, abundant 

 in the lower tide pools, I. Wenman, no. 34-84, 11 Jan. 1934. Ibid., 

 intertidal on islet in Gardner Bay, I. Espanola, no. 34-427, 31 Jan. 1934. 

 Guayas, on the rocky southeastern side of Pta. Santa Elena, Salinas, no. 

 34-460B, 8 Feb. 1934. Ibid., La Libertad, Schmitt no. 12A-33, 19 Jan. 

 1933. 



Codiaceae 



Plants spongy or sometimes calcified, flabelliform or cylindrical, 

 simple or branched, sometimes with distal tufts of free filaments; struc- 

 turally composed of branched filaments, which are commonly twisted and 

 interwoven to produce a spong\'^ axis, at other times roughly parallel and 

 laterally conjoined, and occasionally in the distal parts of the plant free; 

 peripheral branches of the filaments often anticlinally arranged and 

 specialized in form to produce a cortex; sporangia (?) and gametangia 

 lateral near the ends of the filaments. 



KEY TO GENERA 



1. Plants completely uncalcified 2 



1. Plants branched, segmented, the segments disciform and calci- 

 fied, connected by lime-free articulations Halimeda 



2. Plants with an ill-developed and lightly twisted, sometimes 

 matted and sometimes stalklike base, but above the filaments free 

 Chlorodesmis 



2. Plants branched, spongy, with no free filaments .... Codium 



CHLORODESMIS Harvey & Bailey^i 



Chlorodesmis mexicana n. sp.^^ 

 Plate 7, Fig. 2 



Plants forming an expanded turf or cushion, or tufted, to 8 cm tall, 

 developing from a closely matted base, the erect filaments dichotomous or 

 occasionally trichotomous, the branches at their bases articulated by a 



51 In Harvey 1858, p. 29, the genus and the first species C. comosa are cited as 

 "Bail, and Harv.," but in the original publication each species is cited "H. et B.," 

 while the responsibility for the genus is not particularly designated. 



52 Chlorodesmis mexicana n. sp. — Plantae caespitideae aut pulviniformes, 8 

 cm alt., infra implectae, supra filamentis viridibus, dichotomis, super furcas con- 

 strictione et, postrerao, pseudosepto; filamentis 148-185 |x diam. Planta typica in 

 loco dicto Braithwaite Bav, I. Soccoro, Is. Revilla Gigedo, Mexico, legit W. R. 

 Taylor no. 34-24B, 2 Jan. 1934. 



