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ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 12 



4. Branchlets in part turbinate, scattered L. voragina 



4. Branchlets not turbinate, more or less verticillate 



L. obtusiuscula v. corymbifera 



5. Determinate branches and branchlets chiefly opposite .... 



. . . . L. oppositoclada 

 ^'^ 



5. Branching throughout chiefly alternate 6 



6. Habit paniculate, the main axes definitely percurrent L. peninsularis 

 6. Habit coiymbose, the main axes dispersed into the densely cluster- 

 ing terminal branchlets L. congesta 



Laurencia clarionensis Setchell & Gardner 

 Setchell & Gardner 1937b, p. 81, pi. 7, figs. 19-21. 

 Mexico: Is. Revilla Gigedo, on rocks near low tide line, Sulphur 

 Bay, I. Clarion, no. 34-51. 5 Jan. 1934. 



Laurencia Intricata Lamouroux, prox. 



Taylor 1928, p. 179, pi. 34, fig. 8. 



A plant forming small tufts about 2 cm tall, entangled below but the 

 taller erect branches radially alternately divided. This may represent a 

 further development of Setchell & Gardner's L. humilis ( 1930, p. 156, pi. 

 9, figs. 32, 33), but it is even more like dwarfed forms which in the 

 Caribbean are best referred to L. intricata. 



Mexico: Guerrero, tufted on sandy rocks along the shores of Bahia 

 Petatlan, no. 34-578, 2 Mar. 1934. 



Laurencia obtusiuscula Setchell & Gardner, v. 

 corymbifera Setchell & Gardner, prox. 

 Setchell & Gardner 1924, p. 761, pi. 23, figs. 15, 16, pi. 45, fig. b. 

 Ecuador: Archipielago de Colon, intertidal on rocks of an islet in 

 Gardner Bay, I. Espaiiola, no. 34-428, 31 Jan. 1934. 



Laurencia voragina n. sp.^^^ 



Plate 46, Fig. 2 



Plants tufted or turflike, with short basal rhizomatous branches more 



or less coalescent, and with crowded erect axes to 2 cm tall; erect axes 



percurrent with few indeterminate branches, to about 0.5-1.0 mm diam., 



183 Laurencia voragina n. sp. — Plantae caespitideae, infra subrhizomatosae, 

 supra erectae, ad 2 cm altitudine, axibus priraariis pauce divisis, percurrentibus, 

 ramis infra denudatis, supra ramulos ascendentes determinates brevisque arete, 

 alterne radiatiraque ferentibus, his primo turbinatis, basibus vix contractis, adultis 

 paene cylindricis, ad 0.40-0.55 mm diam. Planta typica in loco dicto White Friars 

 Is., Mexico, legit W. R. Taylor no. 39-628, 9 May 1939. 



