23 359 



show a very distincth' rhythmical growth; every three, or more seldom four, pairs 

 of ramuli are especially well developed and from these the next decrease gradually 

 in size. Such a rliythmical growth has also often been found by Svedelius in the 

 Ceylon Caulerpa. How far the segments which arise in this way correspond with 

 the growth of a year I am unable to say but il seems to me quite natural that 

 this should be the case; I should think that the greatest increase occurs about the 

 month of June when the sun is nearly vertically above and the light therefore the 

 most effective. 



The species has hithertho only been found twice in the sea around the island 

 of St. Jan and both times by Dr. Th. Mortensen, e. g. off Ramshead on the 

 south coast of St. Jan in about 50 meters and in the sound between St. Thomas 

 and St. Jan near the little island St. James in about 30 meters depth; at the last 

 mentioned locality I have myself dredged several times without being so fortunate 

 as to found it. 



Geogr. Distrib. Seems to occur in all the warmer seas: The West Indies, 

 Pernambuco, Canary Islands, Red Sea, Japan, Friendly Islands etc. 



3. Caulerpa proliféra (Forsk.) Lam. 



Lamouroux, Mémoire sur les Caulerpes, p. 30. 

 J. Agardh, Till Algernes Systematik, I, p. 11. 

 Weher van Bosse, Monographie, p. 278. 

 Fucus prolifer Forskål, Flora ægypt.-arab. p. 193. 



In the West Indian material we can distinguish the following two forms: 



f. ohovata J. Agardh I.e. p. 11. (Fig. 5.) The leaf oblong-obovate, with few 

 or very often with no proliferation at all. 



f. zosterifolia n. f. (Fig. 6.) The leaves narrow lineate-lanceolate, interrupted 

 and very richly proliferous. This form seems to be rather near the 

 dichotomous form which Janse has mentioned from the Gulf of Naples 

 (Pringsh. Jahrb. Bd. 21, p. 168—9; PI. 6, fig. 6 and 7). 



On the shores of the Danish West Indies Caulerpa proliféra is to be found 

 both littoral and in deeper water, and on exposed and sheltered coasts. Forma 

 obovala I have especially found in deeper water down to a depth of about 

 40 meters; the leaves are here often quite without proliferations at all or if these 

 are present there are only some few. The leaves are broad and short, often nearly 

 ovate; at the apex they are often rather deeply emarginate. Forma obouata also 

 occurs in shallow water near the shores and on even rather exposed localities, 

 I have e. g. found it on the south shore of St. Croix rather near Sandy Point 

 where there is often rather a strong surf and the leaves were also distinctly 

 marked by it. It grows here on low-lying coral reefs in and a little below the 

 surface of the sea and swings to and fro with the action of the waves. The leaf 

 has here a somewhat smaller size, is rather thick and of a leathery consistency 



