ZONES OF THE OCEAN. 405 



of plants, as well as animals. This is termed the 

 LITTORAL ZONE. Its features vary with the geological, 

 or rather mineralogical features of the coast ; and its 

 population., both as to kind and numbers, varies cor- 

 respondingly. 



The line of high-water there is no mistaking : 



" Here, Samphire-banks and Salt-wort bound the flood ; 

 There, stakes and sea-weeds, withering in the mud ; 

 And higher up, a ridge of all things base, 

 Which some strong tide has roll'd upon the place." 



The broad bare tract of shore that intervenes be- 

 tween this line and the now distant water (for the tide 

 is close upon its ebb) will represent the zone in ques- 

 tion, which the returning waves will soon reclaim : 



" There, near the land you may the billows trace, 

 As if contending in their watery chase ; 

 May watch the mightiest till the shoal they reach, 

 Then break and hurry to their utmost stretch : 

 Curl'd as they come, they strike with furious force, 

 And then, reflowing, take their grating course, 

 Raking the rounded flints, which, ages past 

 Roll'd by their rage, will still to ages last." 



A second region is the CIRCUM-LITTORAL, or LAMI- 

 NARIAN ZONE, so called from the abundance of tangles, 

 or sea-weeds belonging to the genus Laminaria, that 

 flourish in it. Vegetable-feeding shell-fish and Naked 

 Mollusca are exceedingly numerous in this space. It 

 is indeed highly productive of various types of animal, 

 and also of vegetable life ; its usual extent may be 

 stated as between low-water mark and where the sea 

 reaches a depth of about fifteen fathoms. 



A third region is the MEDIAN, or CORALLINE ZONE, 



