52 Allan Hancock Pacific Expeditions vol. 26 



Americae Borealis, copy in the Agardh Herbarium, Lund, Sweden. 



Type locality: Coast of California. 



Mexican distribution: Pacific Baja Calif.— T). 5164, 5183, 6494, 

 Cabo Colnett; D. 1167, 1213, Punta Baja; D. 1510, Punta Santa 

 Rosalia; D. 9138, Bahia Asuncion; D. 9509, Punta Abreojos; D. 6711, 

 Bahia Magdalena. 



Ceramium camouii Daws. 



PL 17, fig. 8; PL 18, fig. 1-2 

 Dawson 1944, p. 319, pi. 51, fig. 2-3; Dawson 1950, p. 129; Dawson 1957a, p. 8. 

 Thalli 3-4 mm. high, sparingly dichotomously branched, with 

 occasional secondary lateral branches, 30-40 /x in diam., corticated only 

 at the nodes; apices not forcipate, with a conspicuous terminal cell, with 

 many slender, early-deciduous hairs; cortical bands separating early, 

 usually conspicuously tumid, composed of 2-3 rows of cells, the inter- 

 nodes soon reaching 100-150 /x long; tetrasporangia in whorls, emergent 

 from open, hemispherical, tumid, cortical involucres about 125 [x broad; 

 sexual plants not seen. 



Type: E. Y. Dawson 737-40, July 18, 1940, in Herb. A. Hancock 

 Foundation (55). 



Type locality: Among other minute algae scraped from littoral 

 rocks, Isla Turner off Isla Tiburon, Gulf of California. 



Mexican distribution: Pacific Baja Calif. — Hollenberg 2545, 

 Bahia de Todos Santos near Punta Banda; D. 16171 (Limbaugh) Rocas 

 Alijos, Gulf of Calif. — D. 1751, Bahia Bocochibampo, entangled with 

 Centroceras ; D. 3467, La Paz, entangled with Polysiphonia. 



Ceramium caudatum Setch. & Gard. 

 PL 19, fig. 7, PL 20, fig. 1 

 Setchell & Gardner 1924, p. 776, pi. 27, fig. 55-57; Dawson 1944, p. 317; 

 Dawson 1950, p. 134; Dawson 1959, p. 30. Ceramium avalonae Dawson 1949, 

 p. 17, pi. 5, fig. 31, pi. 14, fig. 56; Dawson 1950, p. 133, pi. 3, fig. 25-26. 



Thalli minute, creeping or entangled among other algae, (2) 4-12 

 (15) mm. high, attached by rhizoids from the nodes, 70-100 /x in diam., 

 or in some forms 180-200 jx in diam. at lower nodes and reduced above; 

 filaments corticated only at the nodes; apices forcipate; internodes 20-30 

 //, long above, 80-300 jx long below (1.5-2.5 diameters) ; nodal bands 

 projecting only slightly, consisting in younger parts of larger, rounded, 

 downwardly directed cells in lower parts of band and smaller, angular 

 cells in upper part, the angular cells in older bands tending to extend 

 down over the larger, rounded cells; tetrasporangia commonly caudate, 

 especially in young stages, or ovoid at maturity, 55-70 fi in diam., 

 projecting, naked, abaxial, 1 or a few at a node; cystocarps subterminal, 

 about 120 fx in diam., surrounded by long, overarching branchlets; 

 spermatangia not seen. 



