58 Rev. M. J. Berkeley on Fiicus Labiilardierii. 



structure of Labillardiere's Alga, respecting which he wintes to me 

 as follows : — " In a paper which I have had in MS. for the last 

 three years, I have proposed Fucus Labiilardierii as the type of a 

 new genus, which I purposed to call Seirospora. Its fruit is 

 altogether unlike that of any other Floridea, and more resembles 

 that of a Fucoidea than anything else. It is a receptacle con- 

 taining a number of cells, each communicating with the surface 

 by a pore, and filled with linear four-jointed sporules V* 



Having premised so far, I proceed to my extracts from Dr. 

 Montague^ s letter : — 



" More than a year since I made an analysis of Fucus LabiU 

 lardierii, of which my specimen left no room for doubt, as it came 

 out of the herbarium of the illustrious traveller. I then disco- 

 vered the singular disposition of the tetraspores, which has been 

 also recognised, as you inform me, by Mr. Harvey. Soon after 

 making this important discovery, I begged you to procure me, if 

 possible, from Dr. Greville, conceptaculiferous individuals. I then 

 told you that the theory of M. Decaisne must fall before the fact 

 of tetraspores contained in conceptacula exactly after the fashion 

 of real spores, and, what is equally curious, converging as the 

 spores of Fucacea, from the periphery to the centre. I compared 

 this singular disposition to what I found in my new genus No- 

 thogenia {Chondrus variolosus, Prodr. Phyc. olim), a Floridea in 

 whose conceptacula the true spores are also convergent. I had 

 purposed to dedicate this new genus to Lenormand, who has done 

 so much for science by his bountiful distribution of species in all 

 parts of Europe, but my intention w^as arrested by the publica- 

 tion of this species under the name of Ctenodus by Kiitzing. 

 After having described minutely the singular fructification of this 

 Alga in my ^ Cryptogamie du Voyage de la Bonite,^ which is at 

 this moment in the press, I immediately drew up the article 

 Ctenodus for the 'Dictionn. Univ. d^Hist. Nat.,' which is on the 

 eve of being published. I have copied both these articles for 

 you, to make you completely master of a question of great in- 

 terest. This is much increased by the Alga you have sent me 

 from Dr. Gre\ille. It confirms a doubt which I have thrown out 

 under the word Delisea (which is not, however, printed at pre- 

 sent), that Calocladia, Grev., does not diiFer from Delisea, Lamx. 

 Diet. Class. The Alga, though received from Dr. Mertens, is 

 most certainly not Fucus Labiilardierii, Turn., but Delisea fim- 

 briata, Lamx. There is the same conceptacular fructification as 

 I have figured in my ' Cryptogamie des Canaries ' under my ge- 

 nus Asparagopsis, and in my ^Ciyptogamie de Cuba' under 

 Thamnophora ; but what will surprise you not a little is that I 

 possess tetrasporic individuals whose tetraspores resemble those 

 of Ctenodus, with this difference, — that they are not convergent, 



