nearest to forma rotunda but in the dimensions and form of the 

 joints it is well separated. 



Var. ty pica is found in shallow water in sheltered localities, 

 especially in the lagoons where it often grows abundantly in the 

 soft bottom but also on more exposed coast and in deep water 

 down to a depth of about 30 meters. It is common at the islands. 



Forma gracilis was only found in Christiansteds Lagoon, where 

 it was growing in shallow water upon the soft bottom. 



Fig. 9. Halimeda incrassata (Ellis et Solander) 

 Lamx. var. monilis, f. robust a n. f. 



About 2 / 3 . 



var. monilis (Ell. et Sol.). 



Barton, The genus Halimeda, p. 27. Corallina monile Ellis and Solander, 

 Nat. Hist. Zooph. 1786, p. 110, pi. 20, fig. c. Halimeda monile Lamx., Sur 1. 

 classif. d. Polyp, corail. (Soc. Philom., Paris 1812, p. 186). Howe, Phycol. Stu- 

 dies III, 1. c, p. 501. 



The specimens referred to this variety have commonly small 

 peripheral utricles as pointed out by Howe, in average maximum 

 diameter from 30 — 44//, but exceptions often occur; one specimen 

 in my collection (nr. 1695) had such groups of cells reaching even 

 a dimension of SO/j. while most of the surrounding cells had a 

 diameter of 35—40 p.. Other specimens from Rendezvous Bay, 

 St. Jan (nr. 1873 b.) had also rather large cells (diameter from 



