99 



19 n thick reaching a length of up to 2 3 times their own 

 breadth. 



All walls in the filaments are thick and stratified not only 

 in the basal cells but also in the cylindrical upper ones (Fig. 104). 



In the cells of the assimilating filaments a well-developed 

 chromatophore is present (Fig. 104). It lies near the upper end of 

 the cell, is campanulate with long prolongations down the wall of 

 the cell and contains a large pyrenoid 

 in its centre. In the cylindrical cells 

 the pyrenoid lies nearer the middle of 

 the cell. 



Of the species described by KJELL- 

 MAN this plant seems to come near 

 to Galaxanra Liebmanni. Besides the 

 small type specimen in Herb. AKE- 

 SCHOUG I have seen some larger ones 

 also collected by LIEBMANN in Mexico 

 and belonging to the Botanical Mu- 

 seum, Copenhagen. These show that 

 the species has a more robust and 

 thicker thallus, the filaments in the 

 medullary tissue are thicker about 19 //, 

 there are often 2 3 large cells at the 

 base of the long assimilating filaments 

 and the basal cell of these are some- 

 what larger (about 75 // long and 55 n 

 broad); also the cylindrical part of the 

 long assimilating filaments is thicker, its 

 diameter reaching 22 p. 



Also G. ramulosa seems to show 

 some likeness to this species, but it 

 differs among other things by the vigo- 



gorous short assimilating filaments the uppermost cells of which 

 are relatively large, and by the thinner, long assimilating fila- 

 ments. 



G. lapidescens was found mostly in sheltered places and in 

 shallow water, e. g. in lagoons and bays, once it was taken in 

 the open sea at a depth of about 12 meters. 



St. Croix: The harbour of Christianssted, off Frederikssted, Lime 

 Tree Bay. St. Thomas: Bovoni Lagoon. 



Fig 104. Galaxaura la- 

 pidescens (Sol.) Lamx. 

 Basal part of an assimi- 

 lating filament with chro- 

 matophores and pyre- 

 noids; below in the cells 

 the nuclei are made visi- 

 ble by staining. 

 (About 400:1). 



Geogr. Distrib. : West Indies. 



7* 



