NO. 10 DAWSON : MARINE ALGAE, GULF OF CALIFORNIA 301 



digitate; cystocarps frequent on frond surfaces, about 450 /x diam., 

 smooth, rounded, about half embedded in frond, protruding only 200-300 

 fi from normal frond surface, with several ostiolar openings. 



Type : D. 649, middle littoral rocks on point 3 miles north of Kino, 

 July 16, 1940. Herb. AHF no. 41. 



The specimens are ample and have a very distinctive habit. It is the 

 smallest species thus far recorded from our area. 



Gymnogongrus divaricatus Holmes 

 Plate 71, Fig. 2 (right) 



Holmes, 1895, p. 255, tab. VH, fig. 3a-b; Okamura, Icones Jap. Algae 

 Vn, p. 16, pi. 310. 



Specimens are known from a single locality in the Gulf, but material 

 is ample and fertile. It seems to correspond in all essential characters with 

 the Japanese species. The truncate or bifid frond-apices and the marginal 

 clavate proliferations serve to identify it. 



D. 94, 120, lower littoral rocks of reef at Turner's Island, Jan. 



Family Gigartinaccae 



Genus GIGARTINA Stackhouse 



Gigartina Teedii (Roth) Lamour. 



Lamouroux, 1813, p. 49, tab. 4, fig. 11 ; Okamura, Icones Jap. Algae I, 

 pp. 163-165, pi. 33, figs. 9-12. 



Several specimens taken from the vicinity of Guaymas correspond 

 satisfactorily with the descriptions and figures of this widely distributed 

 species, known heretofore from southern Europe, Brazil, and Japan. The 

 narrow, complanate fronds, 2 mm. broad, and abundant, delicate branch- 

 ing distingin'sh it from the others of our region. 



D. 47, middle littoral rocks by wharf, Guaymas Harbor, Jan. ; D. & 

 R. 3364, 3286, in shallow water, Guaymas, Dec. 



Gigartina Eatoniana J, Ag. 



Setch. & Gard., 1933, p. 271, pi. 51. 



A few examples are at hand which seem to exhibit the characters of 

 juvenile or immature plants of Gigartina Eatoniana. They show good cor- 

 respondence with the type specimens as illustrated by Setchell and Gard- 

 ner, and until more fully developed material is collected, they are best 



