NO. 1 DAWSON: MARINE RED ALGAE OF PACIFIC MEXICO 51 



base, not tapering perceptibly except from the last 2-3 nodes to the apex, 

 dichotomously branched throughout, without proliferous branches, 

 attached by rhizoids; apices straight to slightly incurved; internodal 

 cells cylindrical, with short conical ends, 30-40 fx in diam. below, 24-28 

 jj. above, 4-6 times as long as broad; corticating bands very narrow, 

 composed of two or sometimes three rows of rounded cells, the larger 

 ones below; tetrasporangia prominent, naked, solitary and secund at 

 the nodes, or occasionally whorled, 30-40 [x in diam. including the thick, 

 hyaline envelope; sexual plants not seen. 



Type: H. L. Mason 36, April, in Herb. California Academy of 

 Sciences (173642). An isotype slide is in Herb. A. Hancock Foundation. 



Type locality: Epiphytic on Codium, Isla Guadalupe, Baja 

 California. 



Mexican distribution: Pacific Baja Calif. — D. 8522, Isla Guada- 

 lupe, on Codium. Gulf of Calif. — D. 286a-40, Puerto Refugio, Isla Angel 

 de la Guarda. 



Ceramium affine var. peninsularis Dawson 

 PI. 17, fig. 9-10 

 Dawson 1950, p. 132, pi. 2, fig. 16-17. 



Like the type of the species but twice the size in all vegetative 

 dimensions, 60-70 /x in diam.; tetrasporangia about 40 fx in diam. 



Type : W. Williams, April 27, 1946, in Herb. A. Hancock Founda- 

 tion. 



Type locality : Dredged from 4-6 m. depth, Isla Concha, Laguna 

 de Scammon, Baja California. 



Mexican distribution: Baja Calif. — Williams, May 1946, Laguna 

 de Scammon; D. 6892, Punta Frailes. 



Ceramium californicum J. Ag. 



PI. 20, fig. 4 



J. Agardh 1894, p. 45; Dawson 1950, p. 123, pi. 3, fig. 18; Dawson 1945, 

 p. 62, misidentified as C. evermannii. 



Thalli 2-3 cm. high or more, attached by a disc supplemented by 

 rhizoids, 400-600 [x in diameter in the lower parts, openly dichotomously 

 branched below with frequent proliferous branchlets, more densely 

 branched above; axes gradually reduced to somewhat forcipate tips, 

 corticated only at the nodes above, the bands 0.5-0.7 times as high as 

 wide, of small, irregular angular cells, truncate above and below, the 

 bands in lower parts extending themselves by acropetal and basipetal 

 secondary growth ; tetrasporangia prominently emergent, at first adaxial, 

 later tending to be whorled, the fertile cortical bands little distorted; 

 spermatangia covering more or less completely the inner cortical bands 

 of upper branches; cystocarps not seen. 



Type: No. 31 of Farlow, Anderson and Eaton, Algae Exsiccatae 



