86 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 26 



small, rounded, blister-like, to 1 mm. in diam., each bearing 100 or 

 more tetrasporangia; sexual plants unknown. 



Type: Dawson 184-40, Jan. 28, 1940, in Herb. A. Hancock 

 Foundation (no. 58). 



Type locality: Dredged from 22-44 m., Puerto Refugio, Isla 

 Angel de la Guarda, Gulf of California, Mexico. 



Mexican distribution: Gulf of Calif. — D. 7070, off Punta 

 Frailes, 40 m. 



Polyneurella hancockii var. rhizoidea var. nov. 

 PI. 37, fig. 2 



Varietas typo similis, basi, autem, prostrata succulenta adhaerente, margin i- 

 bus laminae satis proliferis, hie illic proliferationibus aggregatis radiciformibus 

 ramosis patentibus manifestis; praeditis; sori tetrasporangiales minimi, plerum- 

 que minores quam 300 fi diam. 



Like the type but the base a prostrate, fleshy, adherent structure 

 and the blade margins somewhat proliferous and provided here and there 

 with prominent groups of branched, spreading, root-like outgrowths; 

 tetrasporangial sori very small, mostly less than 300 /x in diam. 



Type: Dawson 6869, Mar. 11, 1949, (consisting of liquid pre- 

 served material and slide) in Herb. A. Hancock Foundation. 



Type locality: Dredged in 20 fms. Bahia de San Lucas, Baja 

 California, Mexico. 



Additional material: D. 6840a, Dredged 10 fms., Bahia de San 

 Lucas, Baja Calif. 



Nienburgia andersoniana (J. Agardh) Kylin 

 PI. 41 ; PI. 42. fig. 1 



Kylin 1935, p. 1; Taylor 1945, p. 280; Dawson 1945, p. 67; Dawson 1949, 

 p. 223; Dawson 1951, p. 53; Dawson, Neushul & Wildman 1960, p. 68, pi. 38, 

 fig. 1. N euroglossum andersonianum J. Agardh 1876, p. 474. 



Thalli to 26 cm. high, consisting of repeatedly pinnately branched 

 ligulate, membranous blades from a stoloniferous holdfast, the prostrate 

 branches with toothed margins; erect axes often stem-like at the base, 

 of variable width above, mostly 3-5 mm., but sometimes only 1.5-2 mm., 

 branching at intervals of 2-7 mm. or more, irregularly alternate, the 

 branches lying for the most part in one plane; blade margins provided 

 with usually prominent, regularly spaced teeth; axes showing a promi- 

 nent midrib in lower parts, often becoming obscure in upper parts; 

 spermatangia in small elliptical or linear sori on tips of segments or on 

 small proliferous outgrowths; cystocarps scattered on both surfaces, 

 projecting, ostiolate; tetrasporangia in rounded sori on blade tips or in 

 small proliferous branchlets. 



Type: An Anderson collection in the Agardh Herbarium, Lund, 

 Sweden. 



Type locality: Santa Cruz, California. 



