PEOCEEDII^QS OF GEOLOGICAL SOCIETIES. 
225 
JSova Scotia." By the Eev. D. Honeyman.— A careful examination of 
the country m the neighbourhood of Arisaig enabled the author to con- 
struct three sections and a map, showing the geological constitution of 
the district. Two of these sections were nearly parallel to one an- 
otlier, running from north to south, and taken some distance apart, 
■while the third was nearly at right angles to the other two; thus a 
tolerably accurate idea of the geology of the country could be ob- 
tained. The author described each of these sections in detail, giving lists 
of the fossils found in the different beds, which proved them to "be of 
Upper Silurian age ; and he further considered that they justified the 
adoption for the subdivisions of these Nova-Scotian Silurians of the 
terms May-hill, Lower Ludlow, Aymestry, and Tilestones, the first and 
third of which had been used for them previously by Mr. Salter. Besides 
Silurian rocks, there occurs in the western part of this district a conglo- 
merate of Lower Carboniferous age, while trap-rocks occur on the north 
and south. 
2. "On some Eemains of Fish from the ' Upper Limestone ' of the Per- 
mian Series of Durham." By Mr. J. W. Kirkby.— The object of this 
paper was to record the discovery of fish-remains in the upper mag- 
nesian limestone of the Permian formation, w-hich is higher in that 
series than any vertebrate remains had been previously known to occur. 
The strata exposed in the quarries were described in detail, especially 
the bed from which most of the fish were obtained, and which is known 
as the " flexible limestone." 
The author stated that at least nine-tenths of the specimens belong to 
Palcsoniscus variant, the remainder belonging to two or three species of 
the same genus, and to a species of Acrolepis. Detailed descriptions of 
the difierent species of fish were given, as also were short notices of the 
species of plants sometimes found associated with them, one of which he 
believed to be Calamites arenaceus, a Triassic species. The occurrence of 
PalcEonisci with smooth scales was stated to be antagonistic to Agassiz's 
conclusion, that the Permian species of that genus have striated, and the 
Coal-measure species smooth scales. In conclusion, Mr. Kirkbj' remarked 
that the fauna of the period appeared to have an Estuarine facies, and he 
expressed his opinion that the fishes were imbedded suddenly, as a result 
of some general catastrophe. 
3. " On the Fossil Corals of the West Indian Islands. Part 3 : Mineral 
Condition." By P. Martin Duncan, M.B. — The resuks of the process of 
fossilization, as seen in the West Indian fossil corals, being very remark- 
able, and having much obscured their specific characters, thus rendering 
their determination extremely difficult. Dr. Duncan found it necessary to 
thoroughly examine their difierent varieties of mineralization, and to com- 
pare their present condition with the diiierent stages in the decay and 
fossilization of recent corals as now seen in progress. Thus the author 
was enabled to show the connection between the destruction of the mi- 
nuter structures of the coral by decomposing membrane and certain forms 
of fossilization in which those structures are imperfectly preserved ; and he 
likewise stated that the fiUing-up of the interspaces by granular carbonate 
of lime and other substances, as well as the induration of certain species, 
during a " pre-fossil " and "post-mortem" period, gave rise to certain va- 
rieties of fossilization, and that the results of those operations were perpe- 
tuated in a fossil state. 
The forms of mineralization described by Dr. Duncan are — Calcareous ; 
Siliceous ; Sihceous and Crystalline ; Siliceous and Destructive ; Siliceous 
VOL. A^II. 
