326 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 3 



referable to this species than to any other. This plant has been recorded 

 from the warmer Atlantic coasts of Europe and America, the Mediter- 

 ranean, the West Indies, and Japan. It is not peculiar, therefore, that 

 it occurs in the Gulf of California. 



The summer plants are the largest, up to 10 cm. high, and appear 

 to be the most mature and typical. All agree, however, in general form 

 of branching and in the sunken nature of the growing points. 



D. & R. 3134e, on rocks along shore of Guaymas Harbor, Dec; 

 D. 312, lower littoral, Willard's Island, Gonzaga Bay, Jan.; D. 47%, 

 lower littoral in shallow bay, Puerto San Carlos, near Guaymas, Feb.; 

 D. 669, cast up at south channel mouth, Tiburon Island, July; D. 673, 

 cast up at Kino, July. 



Genus DIGENIA C. Agardh 

 Digenia simplex (Wulf.) C. Ag. 



C. Agardh, 1822, p. 389; Taylor, 1928, p. 175, pi. 24, fig. 20, pl. 33, 

 fig. 7; Setch. & Gard., 1924, p. 769; Okamura, 1936, fig. 393. 



This species was first found in the Gulf as beach-drift specimens at 

 La Paz. Its wide distribution throughout the world's subtropical seas was 

 markedly extended by that record and may now be further extended by 

 mention of specimens collected by Templeton Crocker on the Zaca Expe- 

 dition of 1936 on the shores of Costa Rica. 



The occurrence in the Gulf has been made better known by recent 

 collections at several stations. It is apparently a lower-littoral plant on 

 rocky shores throughout the area, both in winter and summer, though 

 never very abundant. 



D. 192, 298, lower littoral rocks, Puerto Refugio, Jan.; D. 728, 

 Turner's Island, July; D. & R. 3324, in intertidal pools, cove north of 

 Cabo Arco, Guaymas, Dec. ; D. & R. 3400, Punta San Pedro, Guaymas, 

 Dec. 



Genus LAURENGIA Lamouroux 

 Laurencia paniculata (Ag.) J. Ag. 



J. Agardh, 1863, p. 755; Setch. & Gard., 1924, p. 762; Yamada, 1931, 

 p. 197, pl. 3a. 

 Kylin (1941, p. 42, pl. 3, fig. 38) has described a new species of 

 Laurencia from the coast of California, L. pacifica. He cites the specimen 

 1092 in Phyc. Bot. Amer. sent out under the name L. paniculata as iden- 

 tical with his plant. An already difficult situation is made more compli- 

 cated, and yet we are hardly nearer any solution. A large collection of 



