l6] VEGETATIONAL TYPES OF SEAS 535 



sistant Red Algae or, in less exposed situations, of various Green 

 and Brown Algae, and a lower surf-girdle of large Brown Algae 

 such as DurviUea antarctica. Large Laminariales such as Mac- 

 rocystis pyrifera, and crustose and other Red Algae, together 

 characterize the sublittoral. On the southernmost Australian and 

 New Zealand coasts the benthic vegetation corresponds for the most 

 part to that of southern South America, though Eel-grasses may- 

 abound where the bottoms are sandy or muddy. Thus the same 



o> 



Fig. 175. — A giant Pacific Kelp, Macrocystis pyrifera. (x about lea-) (After 



Skottsberg.) 



Durzillea is a characteristic component of the flora, and the same 

 Macrocystis reaches a reported 60 metres in length (according to 

 recent accounts ; old reports that it attains much greater lengths 

 have not been substantiated). It is interesting to note that a Lichen 

 determined and widely cited as Verrucaria maura, which charac- 

 terizes the supralittoral belt of so many shores in the northern 

 hemisphere, plays a similar role in South America and New Zealand. 



4. In arctic seas the algal flora is rather limited but the vegetation 

 is sometimes luxuriant. Indeed, in the Arctic and Antarctic it is 

 chiefly in the sea that life abounds, the plant and animal communities 

 on land being of relatively poor development. Particularly robust 

 and abundant are some of the gregarious Brown Algae, such as species 

 of Laminaria and Fiiciis, although many Red and some Green Algae 

 usually occur in addition. The vegetation is largely limited to rocky 

 and bouldery substrata, sandy and muddy ones being usually 

 devoid of major growths except in a few situations towards the south- 

 ern extremity of the Arctic where the common Eel-grass (Zostera 

 marina) may form fair ' beds '. 



