2 LIVERPOOL BIOLOGICAL SOCIETY. 
Clyde and Loch Fyne,” by Wiliam Gregory, M.D. Trans- 
actions of Royal Society, Edinburgh, 1857. 
2. Mr. Comber’s ‘‘ List of Diatomaceze Found in the 
Neighbourhood of Liverpool.” Transactions of Historic 
Society of Lancashire and Cheshire, vol. x1., 1859. 
3. ‘The Diatomacee of Hull,’ by Mr. George Norman. 
Published by himself, 1865. This is a most admirable list, 
and little has been added to it up to the present day. 
4, “Tist of Diatomacee Found in the Neighbourhood of 
Chester,’ by Dr. H. Stolterfoth, M.A. Published in the 
Proceedings of the Chester Society of Natural Science, 1874. 
In the following list I shall confine myself to those forms 
of Diatomacee that are found in salt and brackish water 
affected by the tide. Mr. Comber’s list, referred to above, 
contains 137 salt and brackish water species; to these 
I have been able to add 47, making 184 species in all. 
A large portion of my gatherings have been made in the 
estuary of the Dee, but they also extend along the coast of 
North Wales, and I have made a few gatherings in the 
Isle of Man. I have no surface gatherings of more than a 
few miles from the shore, and it is here that my list will, 
perhaps, be most deficient. I have examined many 
gatherings from the Bristol Channel, estuary of the 
Thames, the coast of Devonshire, and Northumberland, 
Tay in Scotland, &c. The general character of the forms 
found on the east and west side of England are much the 
same, but the frequency with which they recur varies 
considerably, and certain forms may be said to mark 
particular localities. This is what would be expected in 
an examination of this lowly order of the Flora. 
For the growth of the Diatomacee heat and sunlight 
are essential, and on these factors depends the development 
of the siliceous skeleton, which is the characteristic of this 
order. As might have been expected in most specimens 
