in the first mode of calcification, an tated under 



minute ■ chambers in the thickness <>i" the calcareous 



d( ilcified pellicle, in which is ;i minute 



pecimen, with .1 microscope giving a magnification 



the distribution of these pon ee fig. 182) 



, - imed by the green chromatophores inside the filaments. 



where bubbles of oxygen were evolved during the photo 



\ii.l inasmuch as the deposition of the calcareous salts would 



tynthesis only, this deposition would necessarily be prevented 



at which the oxygen-bubbles are evolved and cling to the sides of 



In the same way the uncalcified apices of the lateral appendages, described above in 

 ip .is having the function of "windows", escape calcification owing to the presence 

 lineing bubbles of ox\ gen. 



Affinities. The genera as defined in this paper either are calcilied or are uncalcified; 



in .1 given -«muis are either all of them calcilied, or are all of them uncal- 



ve tli.it the two groups are fundamentally and physiologically distinct, and that 



their separation occurred far back in their developmental history. Another fundamental difference 



to which we attach great importance is found in the mode of branching, namely, whether the 



lichotomies are all in one and the same plane or in alternating planes. Imbued 



with the is we have drawn up the following genealogical tables as a concise expression 



of tl lusions to which we have been led. 



II Al 



1- LABELLAR1EAE 



Chlorodesmis 



Avrainvillea 



Uncalcified ancestor 



Flabellaria 

 minima 



Rhipidodesmis 



Callipsygma Boodlcojisi^ 



Rhipilio] 



; 



Rhipilia 



Flabellaria 



pctiol.it. 1 



1 ladocephalus 



