266 Dr Hisserr on the Limestone of Burdiehouse 
whatever, we find plants enclosed in a calcareous deposit in the 
greatest profusion imaginable, what conclusion remains, but that 
such a deposit is more indicative of a fresh-water river or lake, 
than of a sea or estuary ? 
Other points of evidence are perhaps less forcible, although 
they all tend to the same conclusion. 
We find, for instance, that if the inland waters which depo- 
sited the limestone of Burdiehouse, were actually unfavourable to 
the existence in it of acknowledged marine mollusca or conchi- 
fera, they were not unfavourable to countless myriads of ento- 
mostraca, one genus of which, the Cypris, is the recent inhabi- 
tant of fresh-water marshes ; and it may be fairly suspected that 
other genera associated with it were equally so. 
I will not at present dwell upon the presence of the fish dis- 
covered in the-Burdiehouse limestone, although some of the ge- 
nera are found enclosed not only in such sandstones and shales 
as are crowded with plants, but even in coal itself. I shall here- 
after shew, that if their presence does not afford an analogical 
proof, it is at the least circumstantially presumptive, that the 
Burdiehouse limestone has had a fluviatile origin. 
In short, the evidence, in a general point of view, leads to the 
following conclusion. 
There are, it is well known, numerous deposits of limestone 
belonging to the carboniferous group of rocks, in which, to the 
exclusion of any vegetables of a Tropical Flora, nothing but ma- 
rine products, such as corallines, or acknowledged shells of ge- 
nera hitherto found in open seas only, have been discovered. 
With a calcareous deposit of this kind, the comparison of another 
calcareous deposit, destitute of all corallines or marine shells 
whatever, yet containing, in an abundance perfectly remarkable, 
the plants of tropical marshes, along with the entomostraca of 
marsh waters, can surely lead to no other conclusion but the fol- 
lowing :—That while the first formation must have taken place 
