130 LIVERPOOL BIOLOGICAL SOCIETY. 
Mr. Marrat has been for many years engaged in the 
investigation of the Algz of the district, both fresh water 
and marine, and with great generosity he has allowed me 
to make use of his extensive unpublished list. I desire 
also to acknowledge his kindness in placing his notes at 
my disposal, extracts from which I have freely incorporated 
in the following pages. 
Among the more recent treatises on the subject, that 
of Dr. Ferdinand Hauck of Trieste,* in Rabenhorst’s 
Kryptogamenfiora, is one of the most complete and 
exhaustive. I have followed Hauck’s nomenclature, both 
specific and classificatory, save that I have altered the 
family terminations. I have, however, noted the synonyms 
employed by Harvey in his Phycologia Britannica, a 
valuable work, which, though considerably behind date in 
microscopic matters, may still be looked upon as the — 
standard work on the subject for British seas. Where a 
species has not been observed by Hauck I have ape 
Harvey’s specific nomenclature. 
Mr. Marrat draws attention to the fact that “the 
Mersey district is much less productive now than it was 
in former years. In 1860 the seaweeds on our coast were 
cleaner, finer in colour, and more healthy in their general 
appearance than they are now.’ ‘This degeneration is, I 
think, without doubt to be accounted for by the increasing 
amount of impurities in the rivers Mersey and Dee, derived 
from the chemical and other works whose refuse finds 
its way into them. ‘‘The Alge of the Cheshire coast,” 
as Marrat remarks, “‘are peculiar and marked in their 
character. In place of the beautiful well-grown plants 
found on Puffin Island, the coast of Wales, Anglesey, and 
the Isle of Man, we have many dwarfed and stunted 
specimens. Parasites coat and envelope some species of. 
* Die Meeresalgen Deutschlands und Oestereiches, Leipzig, 1885. 

