F. Børgesen: Rhodophyceæ of the Danish W. Indies. 9 



the thallus of this genus "consists of mutually separate filaments 

 which only at a later stage are partly confluent" ; this corresponds 

 with Erijthrocladia irregularis but how far it does with Erythro- 

 cladia subintegra seems more doubtful. Rosenvinge ^has not found 

 young specimens of his plant but such occurred often in my 

 material and as pointed out above the young specimens have a 

 continuous margin with no free ends; in the older specimens, on 

 the other hand, with more irregular margin free ends are present. 

 These older specimens agree very well with the figures 13 and 

 14 of Rosenvinge and also with specimens in a preparation 

 which he has most kindly allowed me to examine. Dr. Rosen- 

 viNGE discusses the possibility as to how far this species ought 

 to be referred to the genus Erythropeltis Schmitz i) but as pointed 

 out by him such a comparison is difficult to undertake as Ery- 

 thropeltis is imperfectly known. In my opinion this genus of 

 Schmitz is very problematic as is also pointed out by Howe ^): 

 "Schmitz, in proposing the new generic name Erythropeltis for 

 Erythrotrichia discigera Berthold (which he cites as the monotype 

 of his new genus without any pro parte reservations), omits any 

 reference to the erect filaments described and figured by Ber- 

 thold". Erect filaments have not been found neither in Rosen- 

 vinge's nor in my plant. On account of these facts it seems to 

 me not impossible that this species ougth to be regarded as a 

 representative for a new genus. 



Yet I want to point out that my plant seems to show much 

 hkeness to the discs found in the newly described Erythrotrichia 

 polymorpha Howe 3) and especially to those forms found upon 

 Chætomorpha cartilaginea and Cladophora fascicularis in which the 

 erect filaments often are wanting. If we compare my figures 

 (Fig. 3 a and b) with e. g. figs. 5, 7 and 9 of Howe it cannot be 

 denied that the similarity is striking, But the cells and sporangia 

 are larger in Howe's plant, the disc is distromatic in the middle 

 and erect filaments are also present. 



St. Thomas: In the Harbour, St. Croix: Northside Estate. 

 Geogr. Distrib. Danish waters. Most probably widely spread. 



^) In Engler & Prantl, "Nat. Pflanzenfam." I, Abt. 2, p. 313, 1896. 

 ^) Howe, M. A., 1. c., p. 80. 

 ') Howe, M. A., 1. c, p. 77. 



