366 



30 



In somewhat deeper water in a depth of about 6 meters I have once found 

 a little form of dwarfish growth. It was dredged ofT Frederikssted at the west 

 end of St. Croix, therefore in the open sea. It grew on a bottom of coral sand. 

 The erect leaves were only some few cm. high and bear some few rather thick 

 and widely separated pinnules. I have only found a small specimen of this rather 

 remarkable form and I may confess that I do not feel quite convinced that it 

 belongs to this species. 



The form of this species which shows the most interest is f. Farlowii, of which 

 fig. 11 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 those which, 

 instead of having the pinnules arranged as normally distichously, bear pinnules in 



Fig. 11. Caiilerpa serlularioides (Gmel.) Howe. f. Farlowii Weber van Bosse. 

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



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 shoots with pinnules in all direc- 

 tion are, as Mme. Weber has pointed out, quite like those in Caiilerpa Selago, to 

 which species C. sertularioides seems to be very nearly related, quite in the same 

 manner as the forma tristichophylla of C. taxifolia connects this species with Cau- 

 lerpa falcifolia. Forma Farlowii is found on the beach in shallow water quite 

 near the surface of the sea and was growing on coral-sand in a smaller basin 

 with fresh water and with some swell. 



A rhythmical growth quite like that described by Svcdelius 1. c. p. 114 and 

 which I have already mentioned for other species is also often to be found in this 

 species in the West Indies. It is present e. g. in the speciiuens I have distributed 

 in WiTTROCK and Nordstedt, Algæ exsiccatæ Nr. 1585. 



