96 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 12 



slender, about 1 cm long, like the base stupose ; the stalk dividing dichot- 

 omously 1-3 times, subcylindrical with remnants of the marginal mem- 

 branes attached; blades ample, several times irregularly dichotomously 

 divided, the segments deltoid toward the base of the plant, the upper 

 divisions tapering to the tips, the sinuses a little rounded, in width to 4-6 

 cm above a forking; stalks continued into the blade and its divisions as 

 definite though inconspicuous midribs which divide notably far down in 

 advance of the division of the blade, so that two forkings of the midrib 

 occur before the first corresponding division of the margin; above the 

 membrane generally two cells thick, together measuring 17-28 /x, but 

 below consisting of a cortical layer and 1-2 medullary layers, the cells 

 similar in size, the total thickness reaching 85 /x,; reproduction unknown. 



This large, broad Dictyopteris is very distinct. The segments are not 

 strap shaped as in most of the genus, but rather tapering; the midribs 

 divide precociously ; the membrane is, for its size, extremely thin. 



Ecuador: Archipielago de Colon, infrequent as dredged from 55 

 meters of? Post Office Bay, I. Santa Maria, no. 34-386A (TYPE), 29 

 Jan. 1934. 



TAONIAJ.Agardh, 1848 



Plant erect, bushy, flabellate, the blade divided into cuneate segments 

 which may be narrow or wider, rather thin and delicate ; apical margin of 

 the blade plane, growing from a marginal row of initial cells, producing 

 medullarj' and cortical layers ; not calcified ; sori slightly immersed in the 

 blade at maturity. 



Taonia Lennebackerae Farlow 



Setchell & Gardner 1925, p. 657, pi. 96. 



Mexico: Baja California, in the lower tide pools, Ba. Thurloe, Pto. 

 San Bartolome, no. 34-614, 9 Mar. 1934. 



ZONARIA C. Agardh, 1817 



Plants of small to large size, decumbent or erect and tufted, flabellate, 

 originally rounded, becoming split and forming spatulate to cuneate lobes 

 with more or less evident concentric hair bands; texture generally firm; 

 attached by rhizoids developed from the lower face of the blade when 

 decumbent, or when erect attached by an irregular holdfast; apical 

 margin of the blades plane, growing from a marginal row of initial cells, 

 producing medullar}' and cortical layers; not calcified; sori at maturity 

 superficial, with paraphyses in the tetrasporangial sori. 



