138 



CEYLON MARINE BIOLOGICAL REPORTS. 



axes have the pinnules in opposite order (fig. 46 b.), and this gives the plant a rather characteristic habit. 

 Its next important character is the relatively considerable length of the pinnule in comparison with the 

 ball-shaped vesicle, which last is also greater than in C. lentillifera in general. In C. longistipitata its 

 diameter is rather above than below IJ mm., and often reaches as much as 2 mm. The length of the 

 pinnules often readies the same measure, i. e., they are also as long as the vesicles, but in every case always 

 longer than half their diameter. Finally, we must point out that the vertical axes are very weak 

 in comparison with the pinnules, and only about twice as broad, and often not even that, but less. This 

 seems to me to be worthy of accentuating, because it has not been pointed out by Webee v. Bosse, who, 

 on the contrary (loc. cit. p. 382), is of opinion that this is a very subordinate character depending only 

 on the age of the plant. 



An examination of fig. 1 a, PL. XXXIV. in Weber v. Bosse' s Monograph shows just as the study 

 of the original specimen itself (No. 16,851) in Agardh's Herbarium, that C. lentillifera. J. G. 

 Agardh, has relatively thicker vertical axes and smaller vesicles, whereas in C. longistipitata the axis in 

 its breadth is most often below or at least never above the diameter of the vesicles (figs. 45, 46). In this 

 respect I have never seen any variation in C. longistipitata. 



Fig- 46- — C. longistipitata (w. v- b). (« 5 x 1, /) 4 x !)• 



For this reason it seems to me to be fully justified if we consider C. longistipitata as a distinct 

 elementary species. My opinion here is supported by the fact that in the district where this species occurs, 

 in the islands in the north between India and Ceylon, it showed itself very uniform, nor are any real 

 lentillifera forms known from Ceylon. Its geographical distribution also seems to strengthen this view. 

 C. lentillifera, J. G. Agardh, is only known from the Red Sea and the western parts of the Indian Ocean 

 (Madagascar), that is, it has Western distribution ; C. longistipitata, on the other hand, is known from 

 the Gulf of Mannar and the Gulf of Siam in the north, to New Guinea in the south, consequently it has a 

 more Eastern distribution ; C. Kihieri, finally, only from the Timor Sea. 



Geographical Distribution. — South India : Paumben Pass ! Pacific (Gulf of Siam). 



