47 



383 



Fig. 25. Caulerpa racemosa (Koisk.) Weber van Bosse var. clavifera (Turner) 



Weber van Bosse. From Longreef (St. Croix). Creeping on a dead coral 



and intermingled witb a Corallinacc. (About 1:1.) 



rhizoids, by means of which it is firmly fastened to the substratum. On the up- 

 ward side the rhizomes are eillier naked or have short often only a centimeter 

 high assimilators 

 with more or less 

 irregularly shaped, 

 often nearly cylin- 

 drical ramuli; only 

 more seldom do we 

 find more normally 

 developed ramuli 

 -swollen at the apex. 

 The ramuli often 

 grow out to new 

 rhizomes (see Fig. 

 27 d and e) and 

 contribute thus to 

 producing the en- 

 tangled tissue of the 

 rhizomes. This form 

 was found in large 

 mats covering the 



most exposed places where Caulerpa is to be found at all. The sea breaks fiercely 

 over the alga which motionless bids defiance to the waves and just in its firmness 

 possesses the necessary protection. Following the plant from these the most exposed 

 places to more sheltered we have the most even transitions to the typical form of 

 var. clavifera. 



Of all Caulerpas occurring in the Danish West Indies, this is certainly the 



one which can 

 grow in the most 

 exposed places, 

 and it is therefore 

 of interest to make 

 a comparison with 

 C. lœtevirens f. laxa 

 of SvEDELius grow- 



ing in the most 

 exposed places of 

 all Caulerpas liv- 

 ing in Ceylon. In 



r^- .„• ^ , ,, , > ,., u .. the way in which 



rig. 2b. Caulerpa racemosa (l-orsk.) Weber van Bosse 



var. clavifera (Turner) Weber van Bosse. these twO formS 



From the reef between the Hurricane Island and St. Thomas. (About 1 : 1.) are fitted to grow 



