6 



DB. G. DICKIE ON ALGiK FEOM RODRIGUEZ. 



Kote on Algio collected l»y Dr. I. B. Balfour* at the Iislaiul of 



Kodriguez. By George Dickie, M.D., F.L.S. 



[Read February If), 1877.] 



This small collection of Algse was made during the sta}' of the 

 Transit-of'A^enus Expedition in the island of liodrigaez in 1874. 

 The short time devoted to the collection of marine forms accounts 

 for its smallness. Of the 52 species and varieties herein enume- 

 nierated, 39 are marine, a number so small that it manifestly 

 cannot be considered a fair representation of the marine alga 

 flora. None of them calls for special mention, as all are widely 



spread in the Indian Ocean and tropical seas. The remaining 

 13 are freshwater forms. G of these have a general range 

 tliroughout Europe, some being quite cosmopolitan. The rest are 

 more restricted in distribution: 2 species, Thorea violacca, Bory, 

 and Cladopliora hamosa^ Dickie, are peculiarly Mascarene ; Chan- 

 transia c(Briilescens^ Mont,, is, strange to say, a Cayenne species ; 

 whilst Conferva Ansonii, Ag., and C. moluccana^ Ag., are each 

 confined to a single island in the Eastern archipelago ; and there 

 is an Indian species (^Chidopliora Moettleri^ Ktz.). 



In addition to those enumerated in the list, fragments of others 

 (such as Vaitclieria^ Odontidium, &c.) occur, but in too imperfect a 

 condition for determination, 



A survey of the freshwater algae of Kodriguez shows us affi- 

 nities with forms from all parts of the world; and while certain 

 of the species are universally distributed, others are limited in 

 their range ; and of these I may note that none are African spe- 

 cies, but they point mainly in an eastern and Asiatic direction, 



Lut of Genera and Species, 



Sargassum vulgare^ Ag. 

 iUcifolium, Turner. 



Turhina^na ornata^ Turner. 



Sydroclailirus cancellatus^ 

 Bory, 



Mesogloia virescens^ Carm. 



Chroospora implexa^ Hering. Sphacelaria rigida^ Hering. 



Digenea simplex, Wulf 

 Laurencia papiljosa^ Eorsk. 

 ' ohtusa, Hudson. 



Dictyota dicliotoma^ Huds. 

 Padina Favonia, L. 

 Zonaria nigrescens^ Sender. 

 Asperococcus sinuosus, Roth. 



* A fuller notice of this collection of Algae will be published in the Roy. Soc. 

 Qcn. Eeport on the Venus-trans. Exped., which, however, may be less eas^-of 

 access to crypt ogamic botanists; hence the present excerpt. 



Jlagelliferay J. Ag. 



