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



119 



filaments consist of very long, nearly cy- 

 lindrical cells (comp. Fig. 128) about 120^« 



broad and about ten times as long; these 



cells are thickest near the base, taper slowly 



upwards growing somewhat thicker again 



at their uppermost ends and have rather 



thick walls. At the upper end these long 



cells carry a whorl of branchlets. These 



are repeatedly subdichotomously ramified 



growing evenly thinner towards their apices 



which end in a single or, usually two, seldom 



three short conical cells (Fig. 129). From 



the basal cells of the branchlets several 



ramified filaments grow out, some upwards 



some downwards, bending themselves round 



the large cells of the principal branches 



(Fig. 128). In the upper parts of the 



branches where the cells are shorter they 



often cover the whole cell (Fig. 130) while 



in the older parts it is only the upper and 



lower parts which they surround. As a rule 



those filaments lie quite loose round the 



cell (compare Fig. 128). 



The branchlets are as is commonly the 



the case in Wrangelia crowded together in the upper, young ends 



of the branches, lower down the whorls of branchlets are more 



distant in accordance with the lengthening of the large central 



cells. In the lowermost part of the branches 

 the branchlets fall off. 



Compared with Wrangelia Argus our 

 plant reminds of this species as to its loose 

 cortical layer but differs from it in its 

 much larger and more loosely constructed 

 thallus and further by the bicuspidate ends 

 of the branchlets. 



And W rangelia penicillata especially differs 

 from this species by its continuous cortical layer 

 in the principal filaments, by the blunt ends 

 of the branchlets, by its much larger size etc. 



Fig. 130. Wrangelia Wrangelia biciispidata has been found in 



bicuspidata now.spec. the sublitoral region down to a depth of 



Part of a young i ^,/^ ^^ 



branch. (About 80:1). about oO— 40 meters. 



Fig. 129. Wrangelia 



bicuspidata nov. spec. 



Apices of branchlet. 



(About 60 : 1). 



