154 THE MARINE BOTANIST. 



HAPALIDIUM. 



" Plant calcareous, consisting- of a single plane of 

 cellules, which are disposed in radiating* dichotomous 

 series, forming* an oppressed, flabelliform frond." 

 Allman. 



HAPALIDIUM PHYLLACTIDIUM.-- WHITE 

 HAPALIDIUM. 



Forms minute, dot-like patches of a whitish 

 colour on algse. Common. '' Each dot consists 

 of one or several fan-shaped fronds, composed of 

 quadrate cells, disposed in dichotomous series. 

 The plant is brittle, colourless, and effervesces in 

 acid." Described, in the Phycologia Britannica, 

 under the name of Lithocystis Allmanni, and the 

 figure of it in that work represents the young* 

 plant, which at a later period becomes much more 

 more lobed and expanded. 



