F. Borgesen: Rhodophyceæ of the Danish W. Indies. 



117 



parts of the principal filaments (Fig. 125). As mentioned above, 

 the large cells in the principal filaments lack a dense cortical 

 layer, yet an attempt at this is present, as from the basal cells 

 in the ramuli some very ramified filaments grow out and bend 

 themselves round the large cells in the principal filaments (Fig. 125). 



The cells in the principal filaments are about 225 [i broad 

 and about four times as long. 



The ramuli are more rcjbust than those in Wrangelia peni- 

 cillata which is the 

 natural outcome of 

 the littoral occurrence 

 of this alga ; the single 

 cells of the ramuli are 

 proportionally short 

 and broad, the fila- 

 ments become evenly 

 narrower towards the 

 apex and end with a 

 short, acute, conical 

 cell (Fig. 126). 



In this species 

 tetraspores only were 

 found (Fig. 126). Like 

 the tetrasporangia in 

 Wrangelia penicillata 

 they are terminally 

 placed upon the ra- 

 muli and are sur- 

 rounded by short fi- 

 laments more closely 

 pressed to the tetra- 

 sporangia than in Wrangelia penicillata. They are tetrahedrally 

 divided and their diameter reaches about 60 p. 



In referring the Wrangelia plebeja of J. Agardh to Montagne's 

 species I make this statement upon specimens determined by 

 Agardh and collected at St. Croix by Ørsted. Certainly the 

 description of Montagne is not especially exhaustive but his 

 figures are of much help. 



This species has been found at St. Thomas: In several places in the 

 harbour and in Store Nordsidebugt. At St. Croix it is as mentioned above 

 collected by Ørsted. 



Geogr. Distrib. : West Indies. Canary Isles. 



Fig. 127. Wrangelia bicuspidata nov. spec. Habit 

 of a plant. (About natural size). 



