124 BOTANICAL MAGAZINE. [v„i. xix. 



regular in the dichotomy. These sections should be in the subgeneric rank 

 and not higher than that. 



I was surprised when I noticed that the former systematists have not 

 paid any attention to the fundamentally differing mode of ramification. 

 If one of them had examined a little further the branches of Mebagonio- 

 lithon {Amphiroa) stelliyerum, Litharthron {Amphiroa) australe, etc., he 

 would undoubtedly have been struck by their unique mode of ramification, 

 so different from that of Corallina or Amphiroa, which was quite familiar 

 to them. Even such a close observer as Harvey, does not mention the 

 peculiarity in describing Litharthron australe. 



I have formerly mentioned in the " Study of Genicula of Corallinte " 

 some points regarding this circumstance. But for a full additional know- 

 ledge on this subject Ave owe much to Madam Weber van Bosse. 



3. Articuli. The external form of the articuli agrees more or less 

 with the generic or subgeneric division. The flat linear articuli of the 

 Eurytion, the hairlike cylindrical ones of Jania, etc., serve to point out 

 its proper group at one glance. But how much it is worthy for generic 

 determination is a matter of question. Very often some species have a 

 puzzling shape of articuli and have effected a vexatious synonymy for the 

 plants. Amphiroa rigida Lamx. and Amphiroa cretacea Endl. have equal- 

 ly cylindrical articuli, and have been classified in the section Euamphiroa 

 Dene. After the anatomical study of both species, however, Weber van 

 Bosse found that the former stands near the Eurytion and the latter the 

 Arthrocardia. Litharthron australe has such shape of articuli as to come 

 near to Amphiroa anceps but the internal structure of its frond claims a 

 quite distinct position. The articuli of Amphiroa aberrans, Amphiroa 

 crassissima, Amphiroa corymbosa, etc., have likeness to those of Cheilo- 

 sporum maximum, etc., but the last species is undoubtedly widely separated 

 in the systematic position from the rest. 



The external shape of the articuli of Coralline should be worth men- 

 tioning to help in defining certain species, when accompanied by the des- 

 criptions of other characters, especially of the propagating organs and the 

 internal structure of articuli. The description of the outward appearance 

 of sterile specimens, therefore, are mostly quite ambiguous and often of no 

 value. 



Madam Weber van Bosse in her newly published paper cleared up 

 the structural difference between the articuli of Amphiroa and of the other 



1) Curallinaceze of Siboga Expedition. 



