134 



restricted to the more sheltered locahties. It is thus rather com- 

 mon in the lagoons, e. g. the Lagoon of Christianssted, where it 

 creeps in the soft bottom; but I have also found this form in a some- 

 what more exposed locality, e. g. behind Long Reef near Little 

 Princess on the north side of St. Croix, but here it is united by 

 many transitional forms with the typical form or with forma bre- 

 vipes. In shallow water it occurs down to a depth of about 2 — 4 

 meters. In such greater depths as 10 — 15 m. in which Svedelius 

 (1. c. p. 115) has found it on the shores of Ceylon I have never 

 seen it. 



Fig. 106. Caulerpn sertuhirioides (Gmel.; Howe f. Fadowii Weber-van Bosse. 

 From Durloes Bay (St. Jan). (About 1:1). 



The form of this species which shows the most interest is 

 f. Faiiowii, of which Fig. 106 gives an illustration. As the figure 

 shows, one finds in the same rhizome leaves which are quite normal 

 like those of f. typica and further leaves which, instead of having 

 the pinnules arranged as normally distichously, bear ])innules in 

 several rows. One can even find the two cases represented in the 

 same leaf as the figure shows, where the third leaf from the growing 

 point is radial at the base but distichous in the uppermost part. 

 The erect leaves with pinnules in all directions are, as M™'' Weber 

 has pointed out, quite like those in Caulerpa Selago, to which spe- 

 cies C. sertularioides seems to be very nearly related, quite in the 

 same manner as the forma tristichophylla of C. taxijolia connects 

 this species ^^dth Caulerpa falcifolia. Forma Farlowii is found 

 on the beach in shallow water quite near the surface of the sea 



