20 



2. Rhizoclonium Keriieri Stockm. 

 Stockmayer, Ueber die Algengattung Rhizoclonium (Verhandl. d. 

 zool.-bot. Gesellsch. in Wien, 40, 1890, p. 582). 



To this species I have referred a few specimens whose cells 

 were about 4 times as long as broad. In one of the collection, 

 found intertwisted among other algse, the filaments 

 had about 19 ^ diam. the cells reaching a length 

 of up to 120 ju (Fig. 8). 



Another form was found growing epiphytic 

 upon Centroceras, to which it was fastened by 

 means of a small disc at the end of the basal cell; 

 its filaments were 15 — 18," thick, and the cells about 

 4 times as long as broad. 



This species was found St. Croix: At Frederikssted; 

 St. Jan: Coral Bay. 



Geogr. Distrib. Europe, Nortli America. 



Cladophora (Ktitz.). 



1. Cladophora uncinata no v. spec. 

 Csespitibus densis, 4 — 5 cm. altis; filamentis 

 rhizoideis multipartitis substrato adfixis, inferne 

 rigidis, transverse annulatim constrictis ca. 110 fj- 

 crassis; membrana crassiuscula. Filamentis super- 

 ioribus tenuioribus, ca. 65 fJ- crassis, Isevibus, cy- 

 lindricis, cellulis diametro 4 — 6-plo longioribus. 

 Ramuhs junioribus 35 n crassis, saepe hamatis. 

 Ramis di-trichotomis, superne ramulis saepe secundis. 



Fig. 8. 



Rhizoclonium 



Kerneri 



Stockm. 



Part of a 



fdament. 



(About 125:1). 



The few specimens collected had a 4 — 5 cm. high, dark green 

 frond. The plant is fastened to the substratum by means of 

 irregularly lobed rhizoids and such also grow out higher up from 

 the nethermost part of the main filaments. Here and for the 

 rest also rather high up in the filaments the wall is thickened, 

 stratified and with annular constrictions (Fig. 9) giving them 

 in this way a moniliform appearance. The main filaments reach 

 a diameter of about 110 f^. In the basal part of the main fila- 

 ments the cells are about 10 — 15 diam. long, often much longer. 

 These very long cells are due to the well known cell-perfora- 

 tions as described by Rosenvinge; in the main filament in the 

 middle of Fig. 9 a cell is just about to grow down. Higher up 

 the filaments are thinner as also the walls, these being here nearly 

 cylindrical without annular constrictions. These thinner fila- 



