268 



CATALOGUE OF THE MARINE ALG^ 



on the authority of Dr. Johnston, who found a single specimen in 

 Berwick Bay, this being the most southerly recorded habitat for 

 the species, which in Britain is extremely rare. Among southern 

 species the most noteworthy are Splicicelaria fillcina and S. fusca^ 

 the former of which I have gathered repeatedly near Seaham 

 Harbour, its hitherto recorded British stations being all on the 

 south coast. 



The following table will convey an accurate idea, so far as 

 our present information extends, of the number of species exist- 

 ing in our district : — 



I have not been able to trace any decided influence exerted by 

 geologic formation on the distribution of Algae, beyond the 

 fact, that along the whole of the magnesian limestone district the 

 number of species is comparatively small. From the foregoing 

 table it will be seen that while thirty- nine of our local species are 

 peculiar to the Northumberland coast, nineteen only belong 

 exclusively to Durham — the remaining one hundred and eighteen 

 being common to both counties. We cannot suppose this dis- 

 crepancy to arise from external conformation, for the coast of 

 Durham presents more abundantly than that of the neighbour- 

 ing county, localities which would seem favourable to the growth 

 of sea-weeds. Excepting, indeed, the stretch of sandy shore 

 between Castle Eden Dene and Hartlepool, one would judge it 

 to be a tolerably good searching ground. Yet such is not the 

 case ; and I do not know that it can be attributed to any other 

 cause than the chemical nature of the rock strata. And I 

 believe that more extended research will rather increase than 



