Marine Algce of the Dunbar Coast. 275 



host plant wliich has naturally a life period sufficiently long 

 to allow time for the development of its fruit, and the escape 

 of its spores ; and, further, that the life period of the 

 epiphyte, irrespective of its time for fruit, is, in the great 

 majority of cases, very much shorter than that of its host 

 plant. 



It will, I think, be seen that this principle is borne out 

 in the examples of epiphytism observed at the Dunbar coast, 

 which I have enumerated in the following pages. 



The classification I have adopted is that of Mr Batters 

 in his excellent work, recently published, on the Marine Algse 

 of Berwick-on-Tweed. 



Class L— CYANOPHYCE^. 

 Order I— SCHIZOPHYCE^. 



Family.— CHROOCOCCACE^. 

 DERMOCAIlPA(Crn.), Bornet. 



1. Dermocarpa prasina (Reinsch), Bornet. 



Epiphytic on Polysiphonia fastigiata, Catenella Opuntia, Cera- 

 miiim ruhrum, &c., between tide marks. Fruit in winter. (G. W. T. 

 1884.) 



Family.— N0ST0CHINEJ5. 



Tribe I. — Oscillarie^. 



MICROCOLEUS, Desmaz. 



2. Microcoleus chthonoplastes {Fl. Dan. ), Thur. 



Found at Broxmouth by !Mr Batters in November 1889. This 

 is the Microcoleus anguiformis of Harvey. 



SYMPLOCA, Kiitz. 



3. Symploca Harveyi, Le Jolis. {Calothrix semiplena, Ag.) 



Near the " Vault," Broxmouth Point, in shallow rock pools near 

 high-water mark, the finest specimens being in the shade. Annual 

 Summer and autumn. (G. W. T. 1882.) 



Tribe II. — Piivulakie^. 

 RIVULARIA, Roth. 



4. RivTilaria atra, Roth. 



On rocks and stones, also epiphytic on small Alg?e in pools 

 near high-water mark. At all seasons. Host plants : Claflnphora 

 rupestris, Sphacelaria cirrho.-^a, Corallina officiiialii;, Eateromorpha 

 percursa, Cladostephus spongiosvs. 



