8 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 17 



diameter, uniseriate below and often for 500-1000 ju, above the base, but 

 then divided by longitudinal and transverse cell divisions to become a 

 monostromatic, ribbon-like blade 4-8 cells wide or more (60-80 /a), or 

 sometimes ultimately to 10-18 cells or 90-170 /x wide; cells more or less 

 rectangular and usually rather regularly arranged in rows; intercalary 

 cell divisions often occurring irregularly throughout upper parts of 

 thallus and producing an irregular outline showing frequent constric- 

 tions ; reproduction by monospores cut off from cells in the broad, ligu- 

 late upper thallus parts (much as in E. pulvinata, pi. 1, fig. 7). 



Type: Holotype not designated, but probably represented by 

 Bory's original collection in Montague's herbarium, Museum d'Histoire 

 Naturelle, Paris. 



Type locality : On Gelidium, coast of Algeria. 



Mexican distribution: Pacific Baja Calif. — D. 1292, on Gas- 

 troclonium, Punta Baja, Apr. ; D. 8360, on Gigartina, Isla Guadalupe, 

 Dec; D. 10518, on Padina, Eisenia, Halidrys and Dictyota, Punta 

 Norte, Isla Cedros, Oct.; D. 10386, on HalidrySj Punta San Eugenio, 

 Nov. ; D. 9094, on Macrocystis, Islas San Benito, Apr. ; D. 9528, 9494, 

 on Laurencia and Padina, Punta Abreojos, Apr.; D. 9169a, on Cysto- 

 seira, Bahia Asuncion, Apr. 



Despite Gardner's rather straightforward description of an expanded 

 basal-cell attachment in his Erythrotrichia porphyroides (Gardner, 1927, 

 p. 237, pi. 24, fig. 4-5), it seems necessary to reexamine that plant to 

 verify its lack of a basal disc and its distinction from E. boryana. 



Erythrotrichia californica Kylin 

 Plate 1, fig. 1 



Kylin, 1941, p. 3, figs. lA-D (invalidly described for want of a 

 Latin diagnosis) ; Smith, 1944, p. 165, pi. 36, figs. 4-5; Dawson, 1944, 

 p. 252. 



Thalli epiphytic, filamentous, unbranched, 1-2 (4) mm. long, 12-14 

 ju. in diameter at the base and in lower parts, 22-40 (50) jn in diameter 

 above, attached by a group of short, thick, branched rhizoidal cells; 

 uniseriate below, of non-uniform, subquadrate cells usually shorter than 

 broad, above multiseriate by longitudinal walls dividing each original 

 cell into 4 or more cells; reproduction by monosporangia cut off from 

 cells of upper parts of filaments. 



Type: Holotype not designated, but probably represented by Hol- 

 lenberg, July 1939, in Herb. Kylin, Botanical Museum, University of 

 Lund, Sweden. Isotypes are in the Dudley Herbarium, Stanford Uni- 

 versity, Calif., and on sheet 55415, including slide 1621, in HAHF. 



