196 THE MICROSCOPICAL NEWS. 
marine, and on one of the slides there is a perfect circular valve 
which can only be compared with Coscinodiscus minor, which 
is, however, a fresh-water species. The question again arises— 
How came the marine species in the deposit? Passing to the 
strata immediately above the firm mud which was purely vegetable, 
I have no: hesitation in stating that the curiously serrated forms 
upon the slides which I have prepared are the silicious cuticles 
of the Dutch Rush, Lgwzsetum hyemale, and probably those 
belonging to the Avena fatua or wild oat according to type slides 
which I have procured for comparison. The deposit has been 
treated with acid. In many of the slides there are numerous 
vegetable spores, which I am not able to identify as spores from 
the Equiseta. In the upper portion of the bank the light greenish 
tinged deposit appeared under the microscope, as before stated, to 
be composed of cylindrical and hollow organisms. After treating 
this with nitric acid in a boiling condition, the residue was found 
to contain a considerable quantity of diatoms, nearly all of them 
easily identified with the very abundant fresh-water species known 
as Synedra. The triangular-shaped ends of the S. capitata are 
very pretty objects, and those frustules which are devoid of these 
broadened extremities may no doubt belong to the S. splendens. 
In the morass there must have been numerous other forms of life 
which left no “ prints upon the sands of time,” but there remains 
yet another slide which will probably interest our worthy vice- 
president, Mr. Stubbs. The active little Cypris, of the Entomos- 
tracan group, led its merry life as usual at some time or another 
during the passing centuries, and I conclude with passing round - 
one slide which contains the carapace or shell, and in the centre of 
the group there is one specimen with its delicate house still 
undivided. 
The several deposits were mounted on glass and passed round 
the table, and all the shells described were named and mounted in 
small glass-top boxes. Drawings of a section of the mud bank in 
its several layers and the various organisms were distributed among 
the members. At the close of the paper, Mr. Bartrum moved a 
vote of thanks to Mr. Moore for the care and labour expended 
in the preparation of the subject so interesting to the city at the 
present time. The paper opened up many curious researches as 
to the physical condition of the early history of the site, and 
especially dwelt upon the theory of the influx of the tides. He 
could not think that the tide had ever reached the bath, notwith- 
standing the presence of the Hydrobia mollucs, and it would 
afford a matter for future research as to whether these creatures 
are really confined to brackish water. Major Davis, F.S.A., who 
was present as a visitor, was invited to take part in the discussion, 
and he gave an interesting description of his researches upon the 
