INTRODUCTION TO CRYPTOGAMIC BOTANY. 



177 



if the first conclusions to which they lead were adopted, the 

 whole system would be soon reduced to the primitive chaos 

 which existed at the time when Turner began his history of 

 Fuci. Most of the genera have representatives in every part 

 of the globe, but the filiform species are more abundant in 

 temperate seas, while a few attain, in warmer countries, their 

 extreme dimensions. 



1, Ceramiace^, Haw. {Ceramiece, J. Ag.) 

 Articulate, often more or less coated with cells. Nuclei naked 

 or involucrate. Spores conglobated. Tetraspores superficial. 

 152. This group contains a portion of those Rhodosperms 

 which are either strictly monosiphonous and filiform, or which 



CaUithamnion corymbosicm. 

 a. Thread with tetraspores, magnified. 

 h. Portion of ditto, magnified more highly. 



c. Thread with naked nuclei, filled with a mass of spores, magnified. 



(GONGYLOSPERMEI.) 



d. Spore magnified more highly. 



From specimens communicated by Mrs. Griffiths.* 



* I have also a specimen from the same lady, showing the antheridia 

 as in Harvey's figure ; but they are so delicate that I am not able to 

 figure them from the dried specimen. 

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