320 
Canada, speaks of the occurrence, in the lower beds of the system, 
of “trunks of drifted trees in the sandstones, at first sight resem- 
bling those of Dadoxylon.... They present,” he says, “a 
regular tissue of long cylindrical fibres, marked on their sides 
with irregular spiral lines, and very distinct from those of modern 
conifers, though their markings suggest the spiral lines on the 
cells of the genus, whence I have taken the name Prototaxites for 
these remarkable trunks. They have medullary rays and regular 
lines of growth, and attained sometimes a diameter of three feet. 
Unfortunately we know nothing of their foliage or fruit, and can 
but suppose that they constitute a prototype of the coniferous 
trees, probably very different from any known in the modern 
world” (‘ Proc. Royal Inst.,’ vol. vi, pp. 169, 170). Mr. Carru- 
thers, however, remarked, in a paper read to the British Associa- 
tion at Liverpool, that ‘‘the supposed Taxineous wood from the 
North American Devonians, to which Principal Dawson gave the 
name of Prototaxites, was a remarkable alga of enormous size” 
(‘ Nature,’ Oct. 6th, 1870). Portions of the supposed wood, trans- 
mitted by Principal Dawson to Mr. Carruthers, showed that they 
belonged to two very distinct plant-structures. One consisted 
exclusively of a regular parenchyma; the other, of which speci- 
mens were exhibited to the Club, was totally different, and it was 
to this that the description above quoted applied, at least as 
far as the microscopic characters. The appearance of medullary 
rays was probably produced by accidental cracks or fissures, no 
structure corresponding to them being shown under the micro- 
scope. The “lines of growth” would have their parallel in 
the pseudo-exogenous stems of the existing Lessonia. In con- 
nection with this alga it is a curious coincidence that Dr. 
Hooker remarks that in the Falkland Isles the ignorant observer 
at once takes the trunks of Lessonia washed up on the shore 
for pieces of driftwood, and on one occasion no persuasion 
could prevent the captain of a brig from employing his boat and 
boat’s crew, during two biting cold days, in collecting this 
incombustible wood for fuel (quoted by Berkeley, ‘Introd. to 
Crypt. Bot.,’ p. 222). 
Rey. E. O’Meara brought under the notice of the Club a spe- 
cimen of earth obtained through the kindness of Rev. Dr. 
McIlwaine, and discovered by W. Gray, Esq., of Belfast, under peat 
at Drumlough, near Lough Ahery, parish of Dromore, Co. Down. 
The material was very rich in diatomaceous forms, of which those 
of most common occurrence are comprised in the following list: 
