Stat. 501. 1 ast of Rotti [sland. 22 m. Mud. coral and Lithothamnion. 



St.u. 311. Sapeh Bay, East coasl oi Sumbawa. Reef. 



I classified 1. c. the plant in question as a denominated form with the following 

 remarks: 1 have heen uncertain whether this plant ought t<> be considered a form of the above 

 s|>ecies (G. Brassica-florida), or should be regarded as a separate one. Only two fragmentary 

 pieces are known, and these appear to be rather young. The plant is, however, in several 

 respects closely allied to G Brassica-fiorida, and, therefore, I place it as a form of the latter 

 until older specimens may be known. It: somewhat diflers from typical specimens of the species 

 both in habit and structure, luit on the other hand it must be borne in mind that G. Brassica- 

 ftorida is a rather varying plant both in habit and even in structure, in the latter respect 

 owing to the fact that it is frequently attacked by lower animals, especially worms, which nearly 

 always show a disturbing influence on the normal development of the layers of tissue. 



With some reservation I now place the plant as an independent species. It is certainly 

 not well distinguished from G. Brassica-jlorida, but, according to the material in hand, it is in 

 some respects so far differing that it seems to be entitled to be kept distinct. Thus it is less 

 inclincd to form thickened crusts, the consistency is looser, with more regular hypothallic layers 

 in the branches and frequently rather numerous grown-in rows of heterocysts, ancl the conceptacles 

 of sporangia are as a rule smaller than in the former. However, as I have already remarked 

 in Lithoth. Adriat. Meer., it must also be observed that the mutual relation between G. Brassica- 

 florida and G. mamillare, a species very nearly allied to the former, has not yet been settled. 

 The species in question seems even to be rather more closely connected with the last named 

 one. It is, therefore, possible that it will prove to be indentic with, or constitutes a form of, 

 G. mamillare, or perhaps both will have to be considered as forms of G. Brassica-jlorida. 

 Typically and well developed specimens of the latter species are till now only known from the 

 Adriatic, the Mecliterranean and the south coast of Africa. Of G. mamillare only a couple of 

 certain specimens are known from Bahia (Brazil), i. e. the types in Harvey's herbarium, but 

 even these are rather young '). Therefore it seems necessary to possess old and well developed 

 specimens from the American coast, in order to be able to settle the delimitation of these 

 three species. 



In addition to the description of the species is to be observed that the branches in old 

 specimens are frequently more densely crowded than in the type specimen, the latter and young 

 one pictured pi. IX, fig. 10. The branches more or less anastomose in the lower part, however 

 in less degree than in G. Brassica-jlorida, and the crust does not grow so thick as in the 

 latter, although a nevv crust sometimes may be developed upon the primary one (PI. IX, 

 fig. 11 — 13). The last quoted specimen is confluent with Litltophxllitm Okamurai ancl Gonio- 

 lithon Reinboldi. In regard to structure, the medullary hypothallium is more marked than in 

 the said species, the cells frequently being 15 — 25 ij., long and 10 — 15 0.. broad, i. e. broader 

 in proportion to the length than in the hypothallium of the crust. Those of the perithallic 

 layer in the branches are often a little smaller than in the perithallium of the crustlike part 



V. II. Harvey. Nereis Australis, or Algae "f the Southern Ocean. Lomion 1S47. p. 109. — As to the occurrence of 

 Harvey 1. c, at Ugoa Bay on the south coast of Africa, cp. nn remarks in Lithoth. Adriat. Meer. 



