Ceramiece?^ callith amnion. 183 



gathered on the shores of France by M. Grateloup, T^•ho 

 communicated specimens to the elder Agardh, by whom it 

 -was pubKshed in the year 1828. Shortly afterwards the 

 indefatigable Mrs. Griffiths discovered magnificent speci- 

 mens growing along the mud-covered base of the harbour 

 pier at Torquay, in which locality it may be found in more 

 or less plenty every summer. From Mrs. Griffiths it received 

 the very appropriate name of ^ Fern-leaf,^ ^ptly expressing 

 the finely pinnated character of the branches, which do indeed 

 closely resemble fairy ferns, so delicate, that it is altogether 

 impossible in a figure to do justice to their beauty.''^ 



18. Callithamnion thuyoideum, Afjardh. 



Minute and beautiful and rare. Fine specimens have 

 been found by Mrs. Gulson, in rock-pools in the Warren, 

 opposite Exmouth ; it has also been obtained in England by 

 Mr. Borrer, Mr. Seance, Mrs. Griffiths, and Dr. Cocks ; and 

 in Ireland by Mr. W. Thompson and Mr. M'Calla. 



19. Callithamnion corymbosum, AgarcUi. (Plate VI. 

 fig. 23, a branch, natural size ; on the left a branchlel with 

 tetraspores, magnified.) 



Hab. On Algae in the sea. Annual. June to September. 



Not rare; from one to three inches high; frond with 



more or less principal stems, with long alternate branches. 



