94 



CELTIC PROVINCE. 



that on the very verge of continual air is distin- 

 guished by the abundant presence of the seaweed 

 named Fucus canaliculars, among whose roots may 

 be found crowds of small varieties of the periwin- 

 kle, called Littorina rudis, especially those forms to 

 which the epithets patula and saxatilis have been 

 applied. These, indeed, range out of the water con- 

 siderably and may be found adhering to the rocks 

 many feet or several yards above high-water mark. 

 On the South- Western, and most of the Western 

 provinces it is accompanied by a neat little black 

 periwinkle called Littorina neritoides, a species which 

 has a wide spread in the world, but is everywhere 

 to be found in similar localities. The second sub- 

 region is marked by the abundance of a small dark 

 rigid sea-weed, called Lichina, painting the rock 

 sides as if with a dingy stripe. With it we find 

 the larger forms of Littorina rudis, abundance of 

 the common limpet (Patella vulgata), the common 

 mussel (Mytilus edulis) and myriads of small seaside 

 barnacles. On parts of the coast where the shore 

 is steep and rocky, even perpendicular, this belt 

 may be seen striping the sea-wall like a broad 

 white band, as if the strong boundary were over- 

 grown by some hoary lichen. When we approach 

 and peer into the cause, we find the whiteness to be 

 owing to the presence of the shells of myriads of 

 barnacles, all of one species of the genus JBalanus, 

 crustaceans, but very unlike crabs. Among them, 

 on the barer portions of the rock, are fast-adhering 



