105 



Corallina Flabellum Ellis & Solander, Nat. Hist. Zoophyt., 1786, p. 124, 

 tab. 24. 



Udotea flabellata Lamouroux, Hist. Polyp, corall. flex. 1816, p. 311, 

 tab. XII, fig. 1. 



Exsicc, WiTTROcK et NoRDSTEDT, Algse exsicc. no. 1202. 



As pointed out by Mr. & Mrs. Gepp Udotea Flabellum is a 

 very variable plant as to its outer appearance, being often simple 

 with entire margin, but most often it is irregularly lobed and 

 has plenty of proliferations. And just as its outer habit is very 

 variable, so also it is found growing under very different external 

 conditions of life. Thus it occurs often in great numbers in the 

 lagoons in shallow water growing upon the muddy or sandy bot- 

 tom. And it is found in more exposed places in those areas of 

 the sea with shallow water and sandy bottom lying behind 

 the coral reefs, which are so common along the shores of 

 St. Croix. And finally it is found in deep water down to a 

 depth of about 30 — 40 meters, here also growing upon loose 

 sandy bottom. 



We may now ask how far the different external conditions 

 of life make differences in the habit of the plant. These are pre- 

 sent of course, even if they do not always seem so very clearly 

 expressed. 



The deep-water form has most often a rather thin thallus, 

 is very distinctly zonate and has a lighter green colour, more- 

 over it is often much divided and proliferous. 



The specimens growing in shallow water but in more exposed 

 places are often very firm and thick, undulated-folded, not zonate 

 or in any case indistinctly, often entire but often also richly 

 lobed and proliferous. 



Near Krause's Lagoon on the south side of St. Croix, 

 growing in shallow water among sea-grasses where small 

 waves were rolling constantly towards the shore, a more 

 slender form with narrow proliferations was found. Elsewhere 

 in the lagoons in quite sheltered places the specimens occur- 

 ring were often quite entire with no proliferations and nearly 

 flat not folded fronds, but proliferating specimens were also 

 often found here. 



Udotea Flabellum is a common species nearly everywhere at 

 the shores of the islands with exception of the most exposed 

 localities. 



Geogr. Distrib. Found in all tropical oceans. 



