- 17 — 



From S. Griffithsiana, of which species I have had specimens 

 collected by Bornet at Saint-Vaast la Hougue for comparison 

 (cfr. Bornet et Thuret, "Etudes phycologiques", pp. 70— 71, the 

 note), my plant differs, among other things e.g. the whole habit, 

 by having roundish carpospores while they are oval in S. Griffith- 

 siana, and the ripe tetraspores are nearly spherical in my plant 

 but oval in S. Griffithsiana. 



My plant seems to have more likeness with Seirospora interrupta. 

 Compared with a tetrasporic specimen in Crouan's "Algues ma- 

 rines du Finistere", No. 137, nevertheless a rather great difference 

 is present in the form of the tetraspores, these being oval and only 

 divided into two cells while in my plant they are nearly spherical 

 and most often tetrahedrally divided. Specimens of Seirospora 

 interrupta bearing cystocarps I have not seen. Buffham (1. c.) 

 mentions seirosporic cystocarps but does not describe the form of 

 the carpospores and Schmitz (1. c. p. 280) who examined a specimen 

 of Buff ham's plant also fails to describe it. 



The plant as mentioned above was found growing epiphytic on 

 Gracilaria Blodgetti at a depth of about 15 fathoms and occurred 

 with tetraspores, antheridia and carpospores in the month of March. 



It is found only in the Sound between St. Thomas and 

 St. Jan: off Ghristiansfort. 



Sperniothaiiinion investieiis (Grouan) Vickers. 



A. Vickers, "Liste des Algues de la Barbade" (Ann. sc. nat., 

 Bot., IX. ser., t. 1, 1905, p. 64); CaUithamnioji investietis Grouan in 

 Schramm et Maze, "Alg. Guadel." ed. 1, 1865, p. 7, ed. 2, 1870— 

 77, p. 141. 



Var. cidaricola nov. var. 



Var. cidaricola a forma tijpica prsecipue differt omnibus partibus 

 plantai majoribus, csespitibus usque V2 cm. et ultra altis spinas 

 Eucidaris trihuloidis densissime incolentibus. Gellulae 16—25;/ crassse, 

 diametros quaternas vel senas longoe. Tetrasporangia pedunculata, 

 solitaria, ovata, triangulatim divisa, 46—57/^ longa, 44— 47^^ lata. 



This nice purple-rose Spermothamnion was found covering the 

 pikes of Eucidaris trihuloides quite densely, the tufts being about 

 ^1-2 cm. high. 



The horizontally creeping filaments (fig. 10 A) are irregularly 

 branched; they are about 30 /i broad and have a very thick outer 

 wall (thickness of the wall 8—10;/). The creeping filaments 



Botanisk Tidsskiift. 30. Bind. 2 



