100 SUBMARINE LICHENS. 



exhibit a clear olive-tint, while their tissues soften, 

 and the frond becomes pliable. The patches I allude 

 to consist of two species or 

 varieties of the genus Lichina; 

 the smaller one, L. confinis, 

 growing just above high- water- 

 mark, where it is wetted by the 

 spray without being submerg- 

 ed ; the larger, L. pygmoRa, 

 growing in places inundated 

 every tide. These little plants have sometimes been 

 considered as A Ic/ce, sometimes as belonging to the class 

 of Lichens. By those who regard them as Algae they 

 are placed in the group of Melanosperms ; but their 

 fructification little resembles that of any of the genu- 

 ine members of this group, while it has a consider- 

 able affinity to that of many Lichens. Most botanists 

 now, therefore, consider them, as their first observers 

 proposed, to belong to the true Lichens. Their subma- 

 rine locality alone connects them with the Algae. But 

 submerged Lichens are by no means anomalous; several 

 undoubted members of that family grow in places ha- 

 bitually flooded, such as the rocky beds of mountain 

 rivulets, or even along the margin of the sea, within the 

 range occupied by the Lichinae. 



About the limit of ordinary low-water, and to the 

 depth of one or two fathoms beyond that limit, the rocky 

 shore is fringed with a broad belt of luxuriant sea- 

 plants, mostly consisting of the family called Laminariece 

 among which some of the larger members of the 

 Fucoidece, and a great number of the F lor ideas, or Red 



