THE EUROPEAN SEAS. 



85 



extends over a great space on the sea-bottom, with 

 an uniformity comparable with that of a tropical 

 savannah." On a stony sea-bed, as usual elsewhere, 

 Fuci take its place. The lower sub-region is that 

 of Laminarice. " Haoc subregio silva maris haberi 

 potest; Laminarice enim, 10 — 15 pedes altse, erectae 

 velut arbores silvae, confertae sunt." The third and 

 lowermost region is that of the purple sea-weed, 

 Regio Rhodospermearum. Its proper range is from 

 8 to 20 fathoms : it is confluent with the last. Its 

 characteristic algae are Iridea edulis, Delesserice, 

 Hutchinsice, Callithamnia, Ceramii, Gigartince and 

 Odonthalia dentata. If this classification of zones 

 of vegetable life be compared with the brief notice 

 I have given of the subdivisions of the littoral and 

 laminarian zones on the British coasts, a close cor- 

 respondence will be perceived ; indeed, the chief 

 difference lies in the stress laid upon the relative 

 value and connection of the sub-regions. 



M. Oersted has given some interesting tables of 

 the relations of the Algae to light, sea-composition, 

 and depth in the locality explored. These I abstract, 

 in order to call attention to this most interesting 

 subject, and because the memoir in which they are 

 contained, is not likely to be within the reach of 

 many British naturalists, having been published in 

 the form of an inaugural thesis. 



