386 Proceedings of Royal Society of Edinburgh. [sess. 
the Museum of Science and Art and for my own collection, a very 
considerable number of specimens from the localities round Edin- 
burgh. 
One result of this large increase of material is that a number of 
undoubtedly new species have to be chronicled. Another result is, 
that the increase of knowledge which this increase of material has 
brought with it, induces me to withdraw several species which I 
myself had previously named, but which I now must place among 
the synonyms. Where species have been otherwise rectified, I have 
not considered it necessary, in a list like this, to occupy space by 
giving the entire synonymy. 
As I hope to take up the cataloguing of the Selachii next session, 
the present list is restricted to the Dipnoi and Ganoidei, including 
the problematical Acanthodei, which ought perhaps, as in the 
opinion of many, to be rather considered as Elasmobranchs. The 
list itself cannot be supposed to be complete, but it will, it is to be 
hoped, be of a certain utility for a time. 
Horizons. 
The Upper Old Red Sandstone (U.O.R.) cannot, I think be asso- 
ciated with the Carboniferous rocks on account of its fish remains, 
which have a greater general resemblance to those of the Lower Old 
Red of the North of Scotland, in spite of the well-known uncon- 
formity which exists between the two sets of strata. In the Car- 
boniferous system two great divisions — Upper and Lower — may be 
adopted, and these again subdivided according to the plan in use by 
the Director-general and Officers -of the Geological Survey. In this 
arrangement the Lower Carboniferous falls into two subdivisions, 
the Calciferous Sandstone Series (C.S.) extending up to the first 
Gilmerton Limestone, and the Carboniferous Limestone Series 
(C.L.) extending from the last-mentioned horizon to the Millstone 
Grit, or Rosslyn Sandstone. And in their turn the Upper Car- 
boniferous rocks fall likewise into two subdivisions — the Millstone 
Grit below, and the Coal Measures (C.M.) above. I have given no 
contraction for the Millstone Grit, as I have seen no fish remains 
from this set of rocks in the East of Scotland. 
It is certainly worthy of note that in this list not one species is 
common to the Upper and Lower Divisions of the Carboniferous 
