112 CEYLON MARINE BIOLOGICAL REPORTS. 



other hand, it seems much more common on the Pearl Banks in the Gulf of Mannar. Thence come 

 fine large specimens from North Moderagam Paar (Gulf of Mannar, leg. Jas. Hornell, 3-4-03) from 

 a depth of about 10m. (sandy bottom with Halophila). 



C. crassi folia from Ceylon is, in respect to the increase of the leaf, defined (even if sometimes, 

 though rather exceptionally, a repeated point growth may be observed) as is t5rpically the case in C. 

 scalpdUformis. 



That such a pronounced growth can occur in C. crassifolia, however, is shown by specimens 

 of the species collected by Lenormand in Venezuela (Herbarium in the Royal Riks-Museum of Stock- 

 holm as well as by several specimens in the Agardh herbarium in Lund. e.g. Nos. 16,457-16,460) : from 

 the creeping horizontal axis rise several assimilators and these have very clear proliferations ; the growing 

 point is, as it were, continued in a petiole which supports a new leaf, or, again, the formation of a petiole 

 is wanting, and only the size of the lobes is diminished, to increase again later on. By this means different 

 stories are built up of longer and shorter branches above one another. In passing, mention may be made 

 of the fact that Lenormand's specimen also very clearly shows that the point of an assimilator can 

 change its character and grow into a rhizome. 



It is impossible for me to distinguish any different forms of C. crassifolia in Ceylon. A few speci- 

 mens have, it is true, somewhat more vertically erected lobes, but they do not seem to have the character 

 even of local forms. 



GeograpJiical distribution. — Ceylon : Weligama, at a depth of about IJm. ! The Pearl Banks 

 in the Gulf of Mannar (at a depth of about 10m.), collected by Jas. Hornell ! J'erguson, Ceylon 

 Algse No. 337! ; Tuticorin, collected by Ferguson (Ceylon Algae No. 412)! 



Red Sea, Indian Ocean, Pacific, Atlantic (from the West-Indies to the Canaries). 



4.— CAULERPA TAXIFOLIA (Vahl) Weber v. Bosse. 



Weber v. Bosse, Monographic des Caulerpes, p. 292. 



Murray, Catalogue, p. 38. 



Exsicc. : Ferguson, Ceylon Algse, No. 80 ! 



f. typica. Pinnules pronouncedly sickle-shaped, curved upwards, 4-5 times as long 



as the breadth of the main axis. 



Syn. Caulerpa falcata, Kutzing, Tab. Phyc. VII., 5, v. 

 f. tristichophylla. Like to the foregoing form, but some of the assimilators have 



tlie pinnules at the base clearly arranged in three rows (fig. 5). 

 f. asplenioides (Greville), Weber v. Bosse, loc. cit. p. 292 (fig. 4). 

 f. interrupta. Like the foregoing, but smaller and between the pinnules almost 



naked parts of the main axis. This variety is formed by I'epeated rhythmical 



point-growth of the assimilator (fig. 6). 



G. taxifolia occurs on the shores of Ceylon in several forms, which, however, are not sliarply 

 distinct, but in places occur mixed torretlier. Most common in the littoral zone is the form described 

 as /. typica, illustrated by Kiitzing under the name of C. falcata (" Tab. phyc," VII., 5, v). 



But I have also observed /. asplenoidcs Grev. growing together with the main form, especially 

 at Matara in pools fiUed at low-water. The form asplenioides is, in its more pronounced forms (fig. 4). 

 fairly characteristic, with its short, straight, not sickle-shaped pinnules, but transitions into the /. typica, 

 are rather common. F. asplenioides seems to occur especially in deep water, and this is also the form 



