THE CEYLON SPECIES OF CAULERPA. 109 



growing axes which all grow out of a more or less pronounced horizontal stem (fig. 1 a). Horizontal axes 

 occasionally start liigher up the vertical branch (fig. 1 b). Both the horizontal and the vertical axes 

 bear roots, round which grains of sand are very firmly fastened, so that they do not come away even if 

 violently shaken in water. With careful manipulation we can observe down in the sand remains of 

 " assimilators " (in Reinke's terminology), that have evidently been sanded over. As, moreover, 

 the older horizontal axes often grow quite deep, this characteiistic reminds us to some extent of 

 many dune grasses, which when covered with sand form their regenerating shoots from axes higher 

 up the stem, by which means the plant continues to keep on the surface of the sand. The danger 

 of over-sanding may be very great sometimes for C. verticillata in its home at Galle, since after heavy 

 showers masses of sand and earth are carried out to sea from the stream, so that the water becomes quite 

 muddy. The subterranean system seems to resemble the rhizomes of the higher plants in that it functions as 

 a store for reserve-material, for its basal branches and axes are quite filled up with starch. The grains 

 of starch, which are comparatively few in the assimilating branches, increase in the lower axes and in 

 the horizontal rhizomes, and are so numerous there that the rhizomes are stained quite dark blue by 

 iodine. They probably function as stores during the plant's resting-time, for in C. verticillata there are 

 clear indications of periodicity. 



Fig. 1. — C. verticillata, j. g. ag. (1 x 1). 



Periodicity. — ^From notes taken by me it seems that C. verticillata at Galle reaches its highest 

 development during the months from November to March, when it occurs in masses at the mouth of the 

 river. On visiting the identical spot in August of the same year (1903) it was scantier, but Ceramia and 

 other Florideae were more abundant. The specimens of this plant collected by Prof. Kjellman 

 (WiTTROCK & NoRDSTBDT, AlgsB exsicc. No. 347) at Galle during the expedition of the " Vega " also 

 date from December. 



Geographical Distribution. — Ceylon : Galle ! Colombo (Ferguson No. 233, 22-1-1871) ; The 

 East Indies : (Tuticorni, Ferguson No. 425) to the Friendly Islands (Harvey) ; The West Indies, 

 in several places. 



2.— CAULERPA SCALPELLIFORMIS ( R. Brown ) Weber v. Bosse. 



Weber v. Bosse, Monographie des Caulerpes, p. 286. 

 Murray, Catalogue, p. 38 



f. intermedia, Weber v. Bosse. 



f. denticulata (Decaisne) Weber v. Bosse. 

 Exsicc: Ferguson, Ceylon Algse No. 411 ! 



Only observed once locally in shallow water on the projecting spit of land on the west side of 

 Paumben Pass (3-4-03) together with quantities of Codium and Chrysymenia. I have not seen it any- 

 where else in Ceylon. 



It is, in general, an extremely large Caulerpa with leaves attaining as much as 36 cm. in length, 

 but with an average of about 20 cm. The lobes vary considerably in shape, being now quite narrow 



