358 



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bottom fixed to gravel and pieces of coral. The rhizome on its under side bears 

 numerous rhizoids which are sometimes finely ramified, sometimes end in small 

 discs by help of which the plant is fixed to the gravel. 



The erect shoots bear two rows of opposite ramuli. These are compressed, 

 the edge turned towards the flat shoot. They are w'edge- or fan-like in shape with 

 the broadest end turned outward and are several times dichotomously divided. 

 The last emarginated ramifications end in a little spine. In the herbarium of 

 Mdme. Weber van Bosse a small specimen of this form is to be found; it was 

 collected by the late Mile. Wickers in the Canary Islands (37) and agrees very 

 well with my West Indian form. The only difference I have observed was that 

 the West Indian specimens were somewhat larger than the Canary specimen and 

 that the rhizome was glabrous in the former but covered with ramuli in the latter. 

 How far the erect shoots in the Canary specimen were flat like the West Indian 



I am unable to say exactly; judging 

 from Mdme. Weber van Bosse's 

 Fig. l**, PI. XXI the midrib seems 

 in every case to be round and the 

 same seems to be the case with the 

 basal part of the ramuli; in the 

 description of the species Mdme. 

 Weber van Bosse writes, p. 269: 

 "Ramules cylindriques à la base". 



I have further had a specimen 

 from Tongatabu for comparison, 

 collected by Grunow "am Corallen- 

 riff", and to be found in the collec- 

 tion of the Botanical Museum in 

 Hamburg. It differs from my speci- 

 mens by being a little smaller, the erect shoots especially are a little narrower and 

 the ramuli consequently shorter; like the Canary specimen and in contrast to 

 mine the plant from Tongatabu has scattered ramuli. 



Judging from a specimen of mine preserved in formalin and collected in 

 about 50 meters, the shoots are first erect but bend soon to the side in such a 

 way that they turn the flat side upward, probably an adaptation so as to be able 

 to interce])t the greatest possible amount of light. 



The greater breadth of the erect shoots is also perhaps to be considered as 

 an adaptation both to the quiet place and feeble light where it grows. 



While it is a common thing in other forms of this species, e. g. f. tomeniella, 



that the erect leaf-bearing shoots bend downwards at an early stage, obtain rhizoids 



and grow further on like the rhizomes fixed to the bottom, this is not to be found 



in the admittedly small material from the West Indies I have had at my disposal. 



If we consider the figure 4 it will easily be observed, that the erect shoots 



Fig. 4 



Caiiterpa Webbiana ;\Iont., f. disticha Weber 

 Bosse. (About 7:1.) 

 From deep water (50 m.) off Ramsliead, St. Jan. 



