38 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 12 



2. Plants moderately broad above, simple or sparingly and sub- 

 equally divided very close to the base; cell arrangement in the 

 upper portion mostly irregular, with some tendency to form 

 longitudinal rows; cell shape rectangular to polyhedral, the 

 lateral wall thick E. flexuosa 



2. Branches relatively few, scattered, similar to the main axis ; cells 



in clear longitudinal rows E. tubulosa 



3. Once generally freely slenderly branched, the branches lateral, 

 progressively larger upward for 1-5 mm above the base; cell 

 arrangement in regular rows throughout ; cell shape rectangular, 

 lateral walls not conspicuously thickened E. lingulata 



3. Progressively 2-several times branched 4 



4. Sparingly primarily branched, the scattered branches similar to 

 the main axis, beset with numerous aculeate branchlets ; cells in 

 longitudinal rows E. salina v. polyclados 



4. Branching freely in successive orders, throughout slender, the 

 smaller branchlets and branch tips ending in a single series of 

 cells ; cells generally in longitudinal series E. crinita 



Enteromorpha flexuosa (Wulfen) J. Agardh 



Collins 1909, p. 203 ; Taylor 1942, p. 13. 



Probably widespread in the tropical Pacific. It is common in the Carib- 

 bean and the tropical Atlantic Ocean. A plant chiefly of the lower tidal 

 range, growing on rocks, sticks, shells, coral fragments, etc. 



Mexico: Is. Revilla Gigedo, dredged in 24-32 meters at sta. 129, 

 Braithwaite Bay, I. Soccoro, no. 34-20, 3 Jan. 1934. Ibid., attached to 

 rocks on the sandy beach, no. 39-60, 18 Mar. 1939. Oaxaca, on dead 

 sticks in shoal water of the lagoon, Ba. Chacahua, no. 39-71, 21 Mar. 

 1939. Costa Rica: in a high protected tide pool. Port Parker near 

 Bahia Salinas, no. 39-74, 25 Mar. 1939. Ecuador: Guayas, at Salinas, 

 Schmitt no. 506, 12-14 Sept. 1926. 



Enteromorpha tubulosa Kiitzing, prox. 



J. G. Agardh 1883, p. 128; Collins 1909, p. 203 (as E. prolifera v. 

 tubulosa) ; Setchell & Gardner 1920, p. 256, pi. 14, figs. 4, 5; Smith 

 1944, p. 51. 



The writer follows Setchell in placing here some material not other- 

 wise satisfactorily disposable, and probably not identical with E. prolifera. 



