welldeveloped rhizoidal, multicellular branches. On the coast of Ca- 

 lifornia are found two species, probably parasitic, but which send 

 into the body of the host, unbranched or even unicellular rhizoids. 

 On Codium mucronatum var. Californicum , grows a dwarf species of 

 Ceramium, C. codicoìa, J. Ag., which sends down into the intrafilar 

 jelly of its host, multicellular, but unbranched rhizoids, ending in 

 comparatively large globular cells. The rhizoidal cells contain chro- 

 matophores of a pale color. This species seems to be partially pa- 

 rasitic, at least. In the warmer vvaters of the coasts of Central and 

 Southern California, there is to be found in some abundance, the 

 form known as Ricardìa Montagne! var. gigantea Farlow (Farlow, in 

 Farlow, Anderson and Eaton, Algae Exs. Am. Bor., N. 58). This 

 specimen, to which Farlow gave the name just mentioned, has been 

 referred by J. G. Agardh to his Erythrocystìs Grevi/lei, as was seen 

 when I, through the courtesy of Dr. Otto Nordstedt, had the op- 

 portunity of examinig the specimens in the Herb. J. G. Agardh at 

 Lund. What Agardh considered to be the types were evidently two 

 specimens (Nos. 36 102 and 3óio3 Herb. J. Ag.) from California, ap- 

 parently received from Greville' s Herbarium and labeled « Dumontia? 

 saccata Grev. Alg. California ». With them were associated in the 

 same cover Farlow\s specimen, N. 58 of the Algae Exs. Am. Bor. 

 (N. 3òioi Herb. J. Ag.) and three other Californian specimens. Ali 

 agreed with the specimen of Farlow, which is undoubtedly a spe- 

 cies of Ricardia and differs from the type of Ricardia Montagna 

 Derbes et Solier, chiefly in its larger size. The length of the Adria- 

 tic specimens is given from 3- io mm. and the Californian speci- 

 mens frequently reach a length of 3o-35 mm. Ali three organs of 

 fructincation, viz: — tetrasporangia, antheridia, and cystocarps — 

 are found on the Californian specimens and agree perfectly with 

 those described for the Adriatic specimens. Finally, to complete the 

 identity, the Californian plants are parasitic on species of Laurencia, 

 chiefly on L vìrgata J. Ag. They occupy the tips of the branchlets, 

 sending down into the tissues of the apical meristem, slender, uni- 

 cellular rhizoidal branches which certainly must draw nourishment 

 from the cells of the host. The proof is complete that Erythrocystìs 

 Grevillei J. Ag. is nothing more than Ricardia Montagnei var. gì- 

 gantea Farlow. I found also, in the J. G. Agardh Herbarium, that 



