io8 



2. Jania rubetu L. Aresch. 



rallina rubens (Linn.) Ellis et Solander p. 120. 

 Areschoug in Agardh, Spec. Gen. et Ord. Alg. 185 1, p. 557. 

 Kui ab. Phyc. t. S. pi. 84, VIII. 



Stat. 33. Bay of Pidjot. [sland Lombok. 

 Stat. [93. Sula Besi I-land. 



3. Jania tenella Ktzg. 



Kützing, Tab. Phyc. t. 8, pi. 85 II. 



Grunow, Die Alg. d. Fidschi, Tonga u. Samoa Ins. erste Folge p. 42. 



Stat. 155. Waigeu Island. 

 Stat. 193. Sula Besi Island. 



( >f Corallina the Siboga brought home only one species, of the subgenus Jania three 

 species; but it proved easier to say that a plant belonged to the subgenus Jania, than to say 

 to which species of Jania it belonged. In all the above-named three species the length of the 

 cells in the node was fairly equal to the length of the cells in the joint. The rows of cells in 

 the joint were not always of such equal length as one would suppose from our fig. 16 on 

 pi. X\T which is not entirely correct in this respect. The rows were usually more like fig. 18 

 on the same plate. 



I have tried hard to name the three species rightly but these slender forms are so 

 extremely puzzling, that I may still have been mistaken. 



Lithothrix Gray. 

 PI. XV, fig. 15. 



Lithothrix is quite an aberrant genus on account of its calcified constrictions that take 

 the place of the horny nodes in all the other genera of the Corallinae verae. lts only species, 

 known as Lithothrix aspergillum Gray, has the same diagnosis as the genus. It is an inhabitant 

 of the West Coast of America. 



The synoptical Key of the Genera has been made with a view to facilitate for students 

 the determination of the Corallineae verae\ the outward characters, so far as they coincided 

 with internal ones, have been used as has also the anatomical structure of the frond and the 

 node. The order in which the different genera are enumerated in this Key, gives no idea of their 

 ;lationship. I believe that these genera, which are outwardly so much alike, have sprung from 

 different members of the group of the Lithothamnioneae. The many affinities existing between 

 Amphiroa and Litkothamnion have been put forward by Solms-Laubach, the observations of 

 inent naturalist have simply been confirmed by my researches, but we have seen at the 

 same time that the old group of Amphiroa breaks up into different genera. 



