ON THE FKESIIWATER ALG^ OF THE WEST INDIES. 279 



shorter and much less deeply bifid than in G. rhyncJwpJiysa. 

 It also appears to be rather more slender than in that species. 

 I therefore venture to contend that C. rhynchophysa of Fisch.J- 

 Mey. & Ave-Lall. Ind. Sem. Hort. Petrop. ix. Suppl. 9, is still* 

 a desideratum to the flora of Great Britain and Ireland. 



/ 



rrt. 





' journ.Linn.5oc.Bot .34 :1899. 



!A further Contribution to the Freshwater Algae of the West 

 Indies. By W. West, F.L.S., and G. S. West, B.A., 

 A.K.C.S. 



[Read 16th March, 1899.] 



The Algae included in this paper were collected mainly in the 

 Island of Dominica by Mr. W. H. Elliott in January and Feb- 

 ruary, 1896, and consisted of dried specimens, numbered and 

 localized. The numbers following the localities refer to the 

 numbered sheets at the British Museum, at which place the 

 specimens can be consulted. 



In 1891 we published a short paper " On some Freshwater 

 Algae from the West Indies " (Journ. Linn. Soc, Bot. vol. xxx.), 

 in which 63 species were recorded from the islands of Dominica 

 and St. Vincent, and the present paper considerably enlarges 

 our knowledge of West Indian species of these plants. Of the 

 63 species mentioned in the previous paper, 21 have been found 

 in other localities, and 66 additional ones are recorded, the latter 

 being prefixed by an asterisk (*). One species (JRhaphidium 

 fractuin) and two varieties (Mesotcenium Kramstai, Lemmerm., 

 var. brevis, and Cylindrocystis tumida, F. Gay, var. domini- 

 censis) are described as new. One alga, Lyngbya majuscula, 

 Harv., is truly a marine species, but it was found in the collec- 

 tion, and is therefore recorded. 



A number of both Desmids and Diatoms were noted from 

 subaerial habitats a sure indication of a constantly moist 

 atmosphere ; these occurred chiefly among patches of Scytonema, 

 Qrchizothrix, and other filamentous algae, and often on trees. 



In the measurements given of the Myxophyceae in this paper, 

 ^' crass. fil." = the diameter of the sheath containing the tri- 

 chomes, and "crass. trich."=the diameter of the cells without 



. the sheath. 



