2 I 



In another paper ') I have pictured three specimens from the south coast of Australia 

 together with specimens from the Mediterranean and the Adriatic. Also the Australian form 

 seems to be identic with f. crassiuscula. Cp. 1. c. pi. I, fig. 4 — 9. It appears to be abundant 

 in certain localities in Port Philip Bay, Victoria. It is richly provided with conceptacles of 

 sporangia. The other reproductive organs are however quite wanting in a rather large number 

 of specimens examined, while in Adriatic specimens cystocarps are rather more common than 

 sporangia, but on the other hand antheridia are very scarce. 



I have shown in the paper mentioned that the Mediterranean as well as especially 

 the • Adriatic forms of the present species are much varying in habit and partly even in 

 structure too. So also in regard to the forms from the Maldives. As remarked 1. c, this appears 

 partly to depend on local conditions, partly on the fact that L. fruticulosum is as a rule 

 more burdened with extraneous objects than most other Lithothamnia, and therefore more 

 irregularly developed. 



In the collection in hand from the Siboga Expeclition occur a number of specimens 

 which, as far as ascertainable, are identic with or 

 very nearly related to L. fruticulosum. However, 

 many of them have been dead or water worn when 

 collected, and germinating plants of one or other 

 species have often attached themselves to such 

 specimens and are gradually covering them more 

 or less. But above all, the specimens are much 

 burdened with extraneous objects, and, therefore, 

 they are more or less stunted or irregularly deve- 

 loped. The nature of the bottom seems in many 

 cases to have been unfit for the development of 

 the species, i. e. it has been rather loose, and there 

 has been too little of hard objects for fastening 

 the plant, which is often burdened also with a 

 mixture of clay and sand. It is frequently attached 

 to fragments of corals or dead calcareous algae, 

 anastomosed with or attached to other living species, 

 but on the other hand also often serving as a 

 substratum to other and especially crustlike Litho- 

 thamnia, as well as numerous Squamariaceae. 

 I have met with up to seven or eight species 

 anastomosed in one piece not more than 2 — 3 cm. in diameter, or one species fully or in 

 part covering the other. Fig. 9 shows samples of such anastomosed species. In addition there 

 are specimens which are partly covered with young crusts of other species, closely and firmly 



Fig. 9. Anastomosed or partly overgrown specimens of: 

 .1. (Stat. 282). 



Lithothamnion fruticulosum (Kütz.) Fosl. 

 Lithothamnion australe Fosl. forma. 

 Lithophyllum Okamurai Fosl.? 

 Lithophyllum sp. 

 Squamariacea. 

 (Corals, bryozoa, worms). 

 B. (Stat. 109). 



Lithothamnion fruticulosum (Kütz.) Fosl. 



Lithothamnion australe Fosl. forma. 



IJthothamnion sp. 



Lithophyllum Okamurai Fosl.? 



Lithophyllum sp. 



Mastophora vielobesioides Fosl. 



Pcyssonnelia sp. 



Another Squamariacea. 



(Corals, bryozoa, worms) \ nat. size. 



1) M. FOSLIE. Die Lithothamnien des Adriatischen Meeres nnd Marokkos, — Wissensch. Meeresuntersuchungen, Abt. Helgo- 

 land. (In press.). 



