— 13 — 



The tetrasporangia (Fig. 7, A and B) were for the most part 

 tetrahedrally divided though cruciately divided also occurred. They 

 were sessile, oblique-obovate or nearly roundish when ripe and 

 35—40;/ broad. 



The cystocarps (Fig. 7, D, E) were, when fully developed, 

 irregularly lobed, binate. I have only succeeded in finding a few 

 procarps; from these it seems to be evident that the carpogonic 

 branch was four-celled; the carpogonium had a rather long 

 trichogyne (Fig. 7 C). 



Antheridia were not present in the material brought home. 



The tetrasporangia and the cystocarps occurred in separate plants. 



The chromatophores were parietal and consisted of shorter or 

 longer, in the young cells rather broad (Fig. 7 B), in the older cells 

 narrower, irregularly sinuate ribbons (Fig. 7 F). Each cell con- 

 tained only one nucleus (Fig. 7 B) but I may remark that I have 

 not succeeded in seeing the nucleus in the very old and thick cells. 



Schmitz has pointed out (1. c. p. 279) that the genus Seiro- 

 spora always has one nucleus in each cell while in Callithamnion 

 there are said to be several nuclei in each cell and this is also 

 mentioned as a difference between the two genera in Engler and 

 Prantl, "Nat. Pflanzenfamilien". 



Nevertheless this statement does not always hold good; even 

 if we as a rule find more than one nucleus in the cells of Calli- 

 thamyiion yet there are several species with one nucleus only. 



In the C. cordatiim nov. spec, mentioned above only one nucleus 

 occurs and Kyi in figures (1. c. p. 151, fig. 30) a single nucleus in 

 each cell of Callithamnion Hookeri; Dr. Rosenvinge has also 

 most kindly told me that in material of C. hyssoides from the 

 Danish Seas he also has found one nucleus only in each cell quite 

 in accordance with what I have found in my West Indian material. 

 In an earher paper Schmitz^) has also mentioned this variation 

 in the number of nuclei in the cells of Callithamnion. 



Upon the whole it cannot be denied that my plant possesses 

 a rather striking likeness to Seirospora (cfr. S. occidentalis men- 

 tioned below) and in this connection 1 also want to emphasize 

 that Schmitz (I.e. p. 283) was of the opinion that Callithamnion 

 Furcellarice most probably belonged to the genus Seirospora. 



^) Schmitz, Fr., Unlersuchungen iiber die Zellkerne der Thallophyten, pars 2, 

 p. 4 (Sitzungsber. der niederrheinischen Gesellsch. fiir Natur- und Heilkunde 

 zu Bonn, 1880). 



