F. Børgesen: Rhodophyceæ of the Danish W. Indies. 361 



All my specimens were sterile. Upon the whole this plant seems 

 seldom to fruit, at any rate it is seldom found in a fruiting condition. 

 Harvey Gibson has given a description of fertile plants. Referring 

 for more detail to his paper*) I shall only mention here that according 

 to him the tetraspores are formed in the cortical layer. They have 

 zonate division. 



The antheridia and cystocarps occur often upon the same plant. 

 The antheridial stands consist of numerous small groups immersed 

 in the cortical tissue, and they are found upon small wrinkled ra- 

 muH (compare also Buffham**). 



The cystocarps are nearly spherical bodies with a short stalk 

 placed upon the erect branches, every articulation bearing one or 

 two of these small cystocarpic branchlets. 1 shall not here enter into 

 a more detailed description of the development and very peculiar 

 construction of the cystocarp, but only mention that the carpospores 

 are formed in great numbers in the interior and that the spores seem 

 to get free by rupture of the cortical layer as no carpostome is found. 



This is a littoral alga found at the islands in sheltered places 

 only. Growing as it does in the shade of the mangroves it is able to 

 grow even a little above the surface of the sea. 



It does not seem to be common at the islands. St. Croix: Chri- 

 stianssteds Lagoon; Saltriver Lagoon. St. Thomas: Bovoni Lagoon. 



Geogr. Distrib.: Seems to occur in nearly all warmer seas. 



Agardhiella Schmitz. 



1, Agardhiella tenera (J. Ag.) Schmitz. 



Schmitz, Fr., System, üebers. Gatt. Florideen (Flora, 1889, vol. 72, 

 p. 435); in Engler u. Prantl, Nat. Pflanzenf., Teil I, Abt. 2, p. 371. 



Rhabdonia tenera J. Ag., Spec. Alg., p. 354; Epicrisis, p. 592. Oster- 

 HOUT, On the life-history of Rhabdonia tenera J. Ag. (Annals of Bot., vol. 

 X, 1896). 



Solieria chordalis Harv., Nereis Bor.-Am., vol. II, p. 121, tab. 23^. 



Rhabdonia Baileyi Harv. in Kützing, Tab. Phycol., vol. XVI, p. 26, 

 pi. 74 c, d. 



*) Harvey, Gibson, R. J., On the structure and development of the 

 cystocarps of CatenellaOpuntia Grev. (Journ. Linn. Soc, Bot., vol. XXIX,. 

 London 1893). 



**) Buffham, T. H., On the reproductive organs, especially the antheridia, 

 of some of the Florideæ (Journal of the Quekett microscop. Club, vol. Ill, 

 Ser. II, p. 5, pi. 21, figs. 10—11). 



