F. Børgesen: List of species. 465 



cells and furthermore the carpogonial branch. If this is normally 

 the case then the difference from Gr. globifera is great; in that 

 species likewise only a single carpogonial branch is present,the 

 carpogonial branch in Gr. globifera being, as described by Lewis^), 

 formed from the second or third peripheral cell. 



The cystocarps are surrounded by an involucrum composed 

 of about eight cells, growing out from the upper end of the terminal 

 joint cell. These cells are long and curved over the cystocarp 

 (Fig. 424" a). According to Zanardini^) and Hauck^) the rays 

 of the involucrum are either undivided or consist of two to 

 three cells. 



The vegetative cells were about 100 /j. broad and four to five 

 times as long. 



The plants were collected in the month of February and 

 March, the one in shallow water near the shore, the other in a 

 depth of about 30 meters. 



The Griffithsia spec, mentioned above on pag. 208, belongs 

 most probably to this species. 



St. Croix: Lt. Princess; St. Jan: off Cruz Bay in the sound between 

 this island and St. Thomas. 



Geogr. Distrib.: Mediterranean Sea, warmer parts of the Atlantic 

 European coast. 



96. Mesothamnion caribaeum Borgs. 



97. Callithamnion cordatum Borgs. 



98. — byssoides Arn. 



99. — spec. 



100. Seirospora occidentalis Borgs. 



101. Antithamnion Butleriæ Collins. 



Collins, Fr. S., The Algæ of Jamaica (Proceed, of the Amer. Acad, 

 of Arts and Scienc, vol. XXXVII, 1901, p. 258). 



Some small fragments (Fig. 425) of this delicate plant were 

 found creeping upon Lophosiphonia ohscura. These seem to ac- 

 cord with the description given by Collins. The main filament 

 reaches a breadth of up to 30 //, its cells a length of about four 

 time the breadth. The wall is thick. In the lowermost part of 



1) Lewis, The Life History of Griffithsia Bornetiana (Annals of Bot., 

 vol. 23, 1909, p. 657). 



2) Zanardini, Iconogr. Phycol. Med.-Adriat. II, p. 39, pi. 50. 



3) Hauck, Die Meeresalgen Deutschi, und Oesterreichs, p. 91. 



Dansk Botanisk Arkiv, Bd. 3. Nr. 1 (1920). 30 



