142 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL.3 



dichotomous, the margins of the blades sparsely denticulate and prolifer- 

 ating into segments which are narrowed at the base and frequently di- 

 chotomous; segments 2-3 mm. broad, with rounded apices, about 100 |x 

 thick, with a sharply delimited cortex; cortical cells in surface view thin 

 walled and sharply angular. Tetraspores and cystocarps unknown. 



Type. — Dredged off Mejia Isl. in 6-11 fms., Puerto Refugio, Angel 

 de la Guardia Island, Gulf of Calif., Mexico, Jan. 22, 1940, E. Y. Daw- 

 son 266 of Allan Hancock Expedition to the Gulf of California, 1940; 

 Herb. Allan Hancock Foundation, AHF no. 2. 



This species is distinguished from all East-Pacific species of Rhody- 

 menia by the following combination of characters: angular-celled cortex; 

 denticulate, proliferating margins ; lack of stipe ; and brilliant color. The 

 morphological habit resembles that of the West Indian species R. occtden- 

 talis. 



(35) RHODYMENIA OCCIDENTALIS Boerg., Mar. Alg. Dan. 

 West Indies, II (1920), p. 387, figs. 371-372. 



Distribution. — ^West Indies. 



(36) RHODYMENIA PACIFICA Kylin, Die Florideenord. Rho- 

 dymen. (1931), p. 21, tab. 9. 



Plate 20, Fig. 14 



Kylin describes this species very briefly, but the photograph of the 

 type shows sufficiently well the typical characters of the species as it 

 occurs in California. Fertile material has not yet been found. 



Distribution. — Coast of California. 



Species Inquirendae 



RHODYMENIA DICHOTOMA Harv., in Hook., Fl. Antarct. vol. 

 I (1845), p. 186, tab. LXXII, fig. 1 ; Laing, Mar. Alg. Subant- 

 arct. N. Zeal. (1909), p. 510, pi. XXIV, fig. 3; Laing, Trans, of 

 N.Z. Inst., vol. 57 (1926), p. 157. 

 In 1909 Laing expressed the opinion that he had specimens which 

 seemed to agree with Harvey's type in the British Museum. In 1926, 

 however, he says, concerning this species, "A doubtful species." 

 Distribution. — New 'Zealand. 



RHODYMENIA ADNATA Okam., Icon. Jap. Alg., vol. VII: 4 

 (1934),p. 35, pi. 318. 

 Distribution. — Gulf of Tateyama, Japan. 



