F. Børgesen: General remarks. 491 



aura, Chrysymenia ventricosa, Chr. Enteromorpha, Chr. Agardhii, 

 Chondria dasyphyUa, Champia salicornoides and Ch. parrula, 

 Mesothamnion caribæum etc. 



Of the Chlorophyceæ the most striking forms were Caulerpa 

 Ashmeadi, C. crassifolia, C. proUfera, C. clavifera, C. cupressoides 

 var. flabellata, C. \\ ebbiana, Struvca elegans, Rhipilia tomentosa, 

 Chamædoris annidata, Udotea cyathiformis, U. verticillosa, U. 

 Flabellum and U. spinulosa, Valonia ventricosa, Penicillus pyrifor- 

 mis, Arrainvillea nigricans, Air. asarifolia, Halimeda discoidea 

 var. platyloba, Anadyomene stellata, Acicularia Schenckii, Dictyo- 

 sphæria farulosa, Codium tomentosum and C. isthmodadum and 

 several others. 



In the strait north of St. Jan between Tortola the algal vege- 

 tation had another composition. Here Chrysymenia U varia was 

 often found in large quantities. 



Some remarks on the geographical position 

 of the West Indian algal flora. 



We see from the investigation now concluded, concerning 

 the algæ found round those West Indian islands which formerly 

 belonged to Denmark, that we have dealt with 90 species of 

 Chlorophyceæ, 45 of Phæophyceæ and 192 of Rhodophyceæ, this 

 last mentioned being therefore by far the largest group. Compared 

 with the very high number of 788 species, which Murray has 

 included in his "Catalogue of the marine algæ of the West Indian 

 region''!), 327, the total number found by me, is certainly not 

 a large number. But we must remember that the Myxophyceæ 

 are included in Murray's hst and moreover, as he himself admits, 

 a large number of the West Indian species in his catalogue are 

 doubtful ones, so this large number will certainly get much reduced 

 on critical examination. 



If we now will try to make a comparison between the West 

 Indian algal flora, as known from the islands in question, and 

 other algal floras, a comparison with other West Indian floras is, 

 of course, the most obvious one. But this I have not done here, 

 as, with the exception of the Bermuda Isles and in lesser degree. 



1) In Journal of Botany, 1888—89. 



