80 REPORT—1858. 
by Prof. Owen in the ‘Annals’ for 1847, is correct, we have abundant proof in the 
structure of the atlas of Pliosaurus, where the os odontoideum is of exactly the same 
shape, and the wedge-bone separated from it by a similar suture. 
It is remarkable that the Kimmeridge Clay species approaches more nearly the 
Ichthyosaurian type than the Lias species, not only in the greater development of the 
os odontoideum and in its lateral edges forming the lateral margins of the atlas, but 
in its supporting the neurapophyses; there is really no essential difference between 
the atlas of this species and the atlas of Ichthyosaurus. 
The atlas of P. Etheridgii and that above referred to, as figured by Prof. Owen, 
show many Crocodilian affinities (the neurapophyses being supported both by the 
wedge-bone and the centrum) ; but the posterior edge of the centrum does not sup- 
port a pair of ribs (plurapophyses), and no trace of ribs articulating with the wedge- 
bone has been discovered. ‘Ihe second vertebra of the same species supports cervical 
ribs articulated to its body; but in all other respects it resembles that of the Crocodile. 
On the Marine Shell Bed of the South Wales Coal Basin, showing the 
presence of Vegetable Remains in the Upper Coal Measures of the District, 
and of Shells and Fish in the Lower Coal Measures, and illustrating the 
eee of forms of life in different stratifications. By G. P. Bevan, 
D., F.G.S. 
The South Wales basin occupies two great divisions—upper and lower measures 
—chemically divided into bituminous and anthracite, the latter principally in Car- 
marthenshire and Western Glamorganshire; Pennant rock series principally at 
Swansea. Average thickness of lower beds of coal, 47 feet; total thickness of are- 
naceous and argillaceous strata, 1500 feet. In this we have seven or eight zones of 
animal life:—Ist. Farewell Rock, lying on the millstone grit, which I propose to 
name Rosser Rock: there are thin seams of coal in this rock containing a bed of 
marine shells, which I have traced for fifty miles; from this bed 1 have obtained 
forty-three varieties. 2nd. Above this is the bottom vein of coal, containing fish 
remains and Spirifer bisulcatus. 3rd. The blue vein, with Anthracosia, Modiolopsis 
and Spirorbis. 4th. Red vein, with Cardiomorpha. Sth. Old coal, with Unio, 
Modiola, and traces of Crustaceans. 6th. Daren Pins, with Myalina quadrata and 
Unio centralis. 7th. Bydellog coal, with Athyris planosulcata, and at Pontypool, Pro- 
ductus scabriculus. 8th. Three-quarter coal, with Terebratula hastata and Mountain 
Limestone species at 700 feet above the Carboniferous Limestone. 9th, Ellid, ferns. 
10th. Black Pins, Unio aquilinus. 11th. Soap vein, shell uncertain. 
On the Vegetable Structure visible in the Coal of Nova Scotia. 
By Professor Dawson, of Montreal. 
Photographs of Quarries near Penrhyn, showing the structure of Granite. 
By Joun S. Enys, F.G.S 
Remarks on certain Vermiform Fossils found in the Mountain Limestone 
Districts of the North of England. By Arpany Hancock. 
After a full description of some peculiar crustacean tunnels or tracks observed 
on the sandy shores of Northumberland and Durham, the author of this paper 
examines in detail certain vermiform fossils obtained in the fine-grained, mica- 
ceous sandstones of Haltwhistle, Wensleydale, and Pateley Bridge. ‘These curious 
fossils, of which there are two principal forms, one grooved, the other nodulous, had 
hitherto been considered to be the remains of worms, or of worm-tubes, or the casts 
of worm-tracks ; but the author objects to this opinion, on account of their great size, 
their dissimilarity to worms, or tubes or tracks of worms; and because certain cha- 
racters exhibited by the fossils themselves preclude the idea of an organic origin. 
He states, however, that they are undoubtedly tracks originally, as now, composed of 
the same material as the slabs upon which they rest; and the high probability that 
they were formed by Crustaceans is deduced from the remarkable correspondence of 
