STUDY OF THE GENICULA OF COKALLTXvE. 41 



related in the preceding chapters. Kltzing j) insisted upon the view 

 that the difference of the internal structure might serve to determine 

 the genera of the Corallinœ. This is not absolutely true. But some 

 of the members, probably almost all, of a section established by 

 DecaiSn£ 8) have common characters in respect of the internal struc- 

 ture. For instance, as would be already understood, most of the 

 Ewytion have the bordered pits in the cellwall, and multizonal 

 genicula which undergo further development. Most of Jania have 

 the zonal arrangement of the periclinal cells irregular, and the unizonal 

 genicula. And Cheilospomm , especially the Eucheilospornm , has a 

 similar character to Jania in this respect. But we can not agree with 

 the opinion that Amp r stdlicjcra which has the peculiarities in the 

 structure, as well as in the function, of genicula should -be classified 

 under the genus Aniphiloa. So also Amp. aspergillum. 



It should be admitted that the morphological characters, both of 

 inner and outer, of genicula may play some important part in 

 systematic survey. It may not be a generic character ; but at least a 

 group may be more sharply defined by the peculiarity, of any, of 

 genicula, rather than by mere external forms of articuli. The position 

 of the genicula in a frond has sometimes a unique character and may 

 well play a part of specific importance. 



These views, together with those of the former writers, are reserv- 

 ed for future discussion. 



1). Ueber die Polyp. Calcif. 



2). Classif. des Alg. et des Polyp. 



