THE MARINE BOTANIST. 215 



into four joints or sporules. These receptacles or 

 swollen tips fall off when ripe; the plant then 

 appears with blunted branches. The spates have 

 not been observed in this species. Grows on rocks 

 and stones between tide-marks. Frequent. Peren- 

 nial. Bearing" fruit in winter. 



DUMONTIA. 



Named in honour of M. Dumont, a French Naturalist, 



Frond tubular, composed internally of a network 

 of interlacing' filaments, externally of a membrane 

 consisting of a single layer of small cells. Fruc- 

 tification: 1. Clusters of spores {favellce) formed 

 on the internal fibres. 2. Cruciate tetraspores dis- 

 persed beneath the outer membrane of the frond. 



DUMONTIA FILTFORMIS.—STRING-LTKE 

 DUMONTIA. 



Frond varying from twelve to three inches in 

 height; bears alternate branches, usually simple, 



