THE CEYLON SPECIES OF CAULERPA. 



117 



The horizontal stem has very big root-branches which spread themselves in tufts of very fine 

 branchlets, on which particles of sand are affixed veiy firmly. The basal parts of the assirnilators are 

 cylindrical and often without branclilets or pinnules for shorter or longer spaces. 



The form tuticorinensis (fig. 12) has not been observed by me otherwise than in preserved specimens, 

 and I can say nothing about its mode of growth. 



Fig. 12. — C. Lessonii, bory, / tuticorinensis n. /. (1 x 1). 



Remarks on the species. — ^Few Caulerpas, one may say, are so variable as those belonging to the 

 group Thuyoideae. Hence, too, the nomenclature of these species is very confused and hard to disen- 

 tangle. With respect to the species in question it seems to me that the following remark should be made 

 to make clear ray opinion about C. Lessonii and its synonymy. 



The alga that Bory (" Voyage de la CoquUle ") described under the name of Caiderpa Lessonii is 

 characterized by its flat main axis, distinguished by relatively great breadth, with usually two-sided 

 branchlets. Even if, as Weber v. Bosse mentions (loc. cit. p. 339) Bory's fig. (or, at least, the 

 copy in Kutzing, 'Tab. Phyc. " V. T., Tab. 6) has been drawn somewhat too broad, in any case Bory's 

 Lessonii must have been characterized by relatively great breadth in comparison with related forms. 

 These latter are to be looked for, on the one side, especially among the G. cupressoides series and parti- 

 cularly among var. lycopodium, Weber v. Bosse, and var. disticha, Weber v. Bosse ; and on the other, 

 also among the C. Freycinetii series var peciinata. But the main axis in tliese forms never, in general , 

 approximately reaches the breadth which has been figured in C. Lessonii, Bory. Clearly, then, this 

 character must be laid stress on when diagnosing C. Lessonii. The fact is that tlie main axis in this 



