On the Marine Algæ from North-East Greenland. 



103 



the other crustiform Florideæ of the collection. The cells of the 

 basal layer are about twice as high as they are broad. Fusions 

 sometimes occur between cells belonging to neighbouring cell-rows 

 of the basal layer. The erect filaments are not connected by any 

 soft gelatinous matter; they are of the same thickness in their 

 whole length or upwards somewhat thicker; their cells are usually 

 VI2 to 2 times as long as broad, more rarely of the same length. 

 The cells contain a single chromatophore lying in the upper part 

 of the cell, apparently cup-shaped. The filaments are sometimes 

 a little branched at the upper end, bearing one or two (or perhaps 



Fig. 2. Cruoriopsis hyperborea. A, portion of the basal layer seen from above 

 and vertical filaments springing off from it, two of them ending in a sporan- 

 gium. B, vertical section of a crust, the filaments somewhat disunited. C, 

 vertical filament branched at the upper end. D, vertical filament bearing a 

 lateral sporangium. E and F, vertical filaments with terminal sporangia. 

 A, ß, D 555:1; C, E, F 345:1. 



more than two) short one- or two-celled branclilets. Possibly rami- 

 fication only takes place by the formation of sporangia. 



The sporangia are placed on the ordinary filaments and are 

 usually terminal but never emerging over the surface of the frond. 

 They may also be lateral on one of the upper joints of a filament 

 and are then usually sessile (fig. 2D); sometimes however two-celled 

 branchlets occur, the upper cell of which will develop into a spor- 

 angium (fig. 2 C). The sporangia are obovate, more rarely shortly 

 oblong; their division is always cruciate, the first dividing wall 

 being horizontal. Sometimes the first division wall is oblique and 

 the arrangement of the spores somewhat irregular. 



Our plant having no sex-organs, its systematic position cannot 

 be determined with certainty. I think however it could be referred 



