the cystocarpic conceptacles of G. Fosliei, which are 800— iioof/.. in diameter, when seen 

 from above, or sometimes even more. in typical specimens of the latter species sporangia have 

 not yet heen found. However, in Lithoth. Mald. and Laccad. I mentioned a specimen of G. 

 Fosliei furnished with the said organs, which are dl about the same size as in G. myriocarpon. 



Put the specimen is not quite typical, as also here the eells are a little smaller than in a 

 tvpical ene from the same place hearing cystocarps, and the heterocysts scantily appearing. 

 ] should be most inclined to consider G. myriocarpon only to be the sporangiadjearing form 

 of a common species including G. Fosliei as the cystocarpic form, the former developing a 

 very small number of heterocysts. I have not yet had the opportunity of comparing more 

 particularly other species of the genus Goniolithon, so as to be able to ascertain a similar state 

 of things. However, in G. Notarisii sporangia-specimens partly exhibit a rather large number 

 of h< >ts, partly they are scarce. In G. elatocarpon, a species closely allied, I have not 



seen heterocysts. Of this species, however, only a single specimen is known. The latter species 

 stands in almost the same relation to G. Notarisii as G. myriocarpon to G. Fosliei, e. g. the 

 cells frequently being smaller. It would be of considerable interest to realize the said relations 

 particularly in regard to sexual and asexual forms of one and the same species within the 

 genus Goniolithon, as well as the nearly allied genus Melobesia. Thus in the latter genus too 

 the mutual relation between e. g. M. farinosa and M. Lejolisii is not yet fully elucidated. 

 These species are in fact hardly distinguishable except for the heterocysts appearing in the 

 former, and perhaps a small difference in the size of the cells. 



I do not venture, however, at present to unite G. myriocarpon and G. Fosliei, partly 

 owing to the mentioned difterences in structure, partly and especially because the supposed 

 relations in regard to the reproductive organs and the different appearance of the heterocysts 

 are not yet settled. 



Occurence: The plant seems to be rather widely dispersed, but apparently not 

 occurring in great number at any of the quoted stations. 



Area: Indic: The Red Sea. 



2. Goniolithon Fosliei (Heydr.) Fosl. Fig. 19; PI. IX, fig. 1 — 5. 



Lithoth. Adriat. Meer. 



Lithothamnion Fosliei Heydr. Corall. in Ber. der Deutsch. Bot. Gesellsch. 1897, p. 58; ex 



parte sec. spec. 

 Lithophyllum Fosliei Heydr. 1. c. p. 410. 



Stat. 71. Pulu Barang, near Makassar. Reef. 

 Stat. 78. Lumu-Lumu-shoal, Borneo-bank. Reef. 

 Stat. 91. Muaras-reef, inner side: East coast of Borneo. 



Stat. 303. Haingsisi, Samau Island. Reef. 



As for the apprehension of this species I refer to my remarks in Melob. Arb. Heydr. 

 ]). S and Lithoth. Mald. and Laccad. p. 470. An audiëntie specimen, distributed by Hevdrich 

 himself, is represented pi. IV, fig. 1, and a vertical section of the same specimen fig. 19 A. 



