CORALLINACEvE. 129 



Dr. Harvey says of this species " that it differs from 

 the more common /. rubens, chiefly, if not altogether, in 

 the form of the lower articulations, much as Corallina 

 squamata differs from C. officinalis. The species has 

 been generally kept up by all authors since the time of 

 Ellis, who first distinguished it. On the British shores 

 it is most common on the southern coasts, while J. rubens 

 is found all round the islands." 



Genus XLIX. MELOBESIA. 



Frond solid, crustaceous, opake, of irregular shape, with- 

 out joints, having a cellular structure hidden by a calcareous 

 deposit, which may be removed by soaking the plant in acid. 

 Spore-threads erect, oblong, four-parted, in conical concep- 

 tacles which have a terminal pore, and are scattered on or 

 sunk in the surface of the frond. — Melobesia, named after 

 Melobosis, one of Hesiod's sea-nymphs. 



In external appearance the species belonging to this 

 genus are extremely unlike anything which we are ac- 

 customed to consider a plant. Their mode of growth is 

 somewhat similar to that of Lichens, and certain genera 

 of Fungi ; but they differ even from these in the import- 

 ant particular of their calcareous, stony structure. Some 

 of them adhere so closely to the rock on which they 

 grow as to be inseparable from it, and for this reason 

 they are most uncomfortable inmates of an herbarium, 

 and require to be kept in a drawer or box by themselves. 

 Dr. Harvey has figured and described nine species in his 

 ' Phycologia Britannica/ but he appears to consider that 

 four of these are founded on insufficient characters. 

 There is, in fact, a great variety of opinion among writers 



K 



