6o 



Stat. [09. 1'uhi ! 1!. Sulu Archipelago. 13 m. Lithothamnion bottom. 



Stat. 25S. Tual, Kei Islands. 8 — 12 m. Lithothamnion, sand and coral. 

 Stat. 303. Haingsisi, Samau [sland. Reef. 



When I classified this species 1. c. I considered it to be closely allied to Lithophyllum 

 fasciculatum, a species which, however, comes very near to L. racemus (PI. XI, fig. tij. I then 

 possessed specimens only of the form of the species which I have afterwards named f. augularis 

 (PI. XI. fig. 11 — 12). Simultaneously with the latter I described the form Japouica, which is 

 strongly resembling L. racemus in habit. (PI. XI, fig. 13). The species includes some specimens 

 which I have formerly considered referable partly to L. fasciculafum \ partly to L. racemus. 



I will not here enter more fully upon the question whether this species is in fact specifically 

 distinguished from L. racemus, nor on its relationship to other nearly allied species, as L. 

 Kaiserii Heydr., L. pallescens Fosl. (including L. californiense Heydr.), L. affinc Fosl., L, 

 fasciculatum (Lam.) Fosl., and L. Andrussowii Fosl. — I have already remarked in Lithoth. 

 .Malei, and Laccad. that I keep them distinct until they have been more fully examined in a 

 larger amount of material from different localities. This particularly concerns the first named 

 three species. I regard L. Okamurai as an independent species owing to the fact that the cells 

 are as a rule longer in proportion to the breadth than in L. racemus. In this respect, however, 

 the species in question can hardly be distinguished from L. fasciculatum, the latter hitherto with 

 certainty known only from the west-coast of Ireland : ). Besides, the conceptacles of sporangia 

 are a little more peripherical than usual in L. racemus, although 110 certain limit is to be drawn 

 in this respect. In addition, among a rather great number of specimens examined from the coast 

 of Japan I met with a single one, in which a part of the lower layers of tissue exibits alter- 

 nating long and short cells. Such ones have never been seen in L. racemus. In this respect 

 the plant approaches to L. pallescens from the Pacific coast of America. In the latter species 

 the cells are, however, more frequently alternating long and short, though in such cases often 

 rather irregularly. This is also the case with L. a/'pue from the Red Sea. The last named 

 species is partly closely allied to L. racemus, partly to L. pallescens in structure, whereas in 

 habit it comes near to delicate forms of L. Kaiserii, to which it in part also approaches in 

 structure. Therefore, it is necessary to have access to a number of well developed specimens 

 particularly from the Red Sea and from the Pacific coast of America in order to be able to 

 settle the delimitation of the said species or forms 2 ). 



I have remarked before in this paper that L. Okamurai sometimes also recalls other 

 species than the above mentioned ones in habit, species which however in other respects are 

 quite differing. Thus it occasionally comes very near to certain forms of Goniolithon Reinboldi 

 as to habit. Cp. pi. X, hg. 6. Xow and then it also gets confluent with the latter, as to be 

 seen on pi. XI, fig. 16, where some branches belonging to G. Reinboldi are marked with a 

 cross. Besides, pi. IX, fig. 13 represents a specimen which in the main belongs to Goniolithon 

 laccadivicum , sharing however substratum with the species in question as well as Goniolithon 



1) M. Foslie. New or critical calcareous Algae. — Det Kgl. Norske Vidensk. Selsk. Skrifter 1899. n° 3. Trondhjem 1900. p. 30. 



2) I intend later on to publish an account of the unarticulated Corallinaceae, with pictures of all the species and forms 

 known to me. 



