F. Borgesen: Rhodophyceæ of the Danish W. Indies, 



213 



irregularly arranged walls in a number of small cells or rather short 

 filaments, the end cells of which are the antheridia (Figs. 196 d—h). 



The procarp occurs 

 terminally upon short 

 branchlets (Fig. 195 b). 

 When fully developed it 

 (Fig. 197) consists of a 

 basal cell from which the 

 carpogonial branch issues, 

 and a sterile cell nearly 

 opposite to it ; in the 

 middle we find the large 

 auxiliary cell and above it 

 a sterile apical cell. The 

 carpogonial branch is com- 

 posed of _ 3 cells and the pjg ^gg, Mesothamnion caribaeum nov. 

 carpogonium with the spec. Development of cystocarps. a, the 



trichop-vTip • thp last mpn- auxiliary cell is divided "in three cells, b, 

 iricnogyne, tne last men- ^^^^ advanced stage. (About 200:1). 



tioned is rather robust, 



nearly cylindrical and very persistent. By means of staining in 

 Mayer's hæmalum I have been able to see the nucleus clearly 

 as well in the auxiliary cell as in the other ones of the procarp 



except in the carpogonium, this 

 most probably being due to the 

 bad preservation of the material, 

 this having been kept in rather 

 weak spirit. 



After the fertilization the auxili- 

 ary cell increases in size, and soon 

 two cells are cut off, one at both ends 

 of it (Fig. 198 a). These cells again 

 are divided into smaller ones (Fig, 

 198 b). 



Not having had sufficient mate- 

 rial I have not been able to follow 

 the development in detail, but the 

 Fig. 199. Mesothamnion cari- result of the further growth is that 



sent. (About 120:1). of several larger and smaller round- 



ish bodies consisting of the nume- 

 rous carpospores (Figs, 199 and 200). Of these bodies the two 

 on each side are the largest; so far I have been able to follow 



