376 
THE GEOLOGIST. 
SO that it has obtained the name of iandscape-stonc, near Bristol, 
Avherc it is frequently quarried, and used for ornamental 
purpoEcs. It contains a small bivalve, which may be a fresh- 
water shell Cypris,* and three species of Monocolyledonous aquatic 
plants belonging to the family Naiades, some genera of which may still 
be observed in ponds and ditches, though others inhabit the sea. This 
limestone is readily recognized by its position, fossils and lithological 
structure, and is distinct from the overlying band. It is well exhibited 
at Wainlode, "Westbury, and Aust Passage, where it is considerably 
thicker, and contains some well-preserved insects and two new species 
of small fish. Twelve feet of yellow clay and black shale divide the 
above from the celebrated " bone-bed," of which there are two layers at 
Wainlode Cliff, the upper one being a hard sandstone, the surface of 
which is covered with various markings and tracks of moUusks and 
marine worms, and the other, about ten feet lower, of a dark colour, 
full of pyrites, and almost composed of bones, teeth, and scales offish 
and saurians ; at Coombe Hill, "Westbury, and Aust it is much 
thicker, and contains some singular palatal teeth of Ceratodus. Two 
feet of black shale separate this from the green and red marls of the 
Trias, or New Eed system. From the characters of the fossils which 
mark these "bone-beds," it has been inferred that they would be more 
correctly assigned to the Trias ; at all events, there is something 
peculiar and distinctive about them ; and it is a striking fact that 
though sometimes blended together, they jcan be traced even into "Wales, 
the main mass still being made up of bones, scales, teeth, and coprolites of 
fish and saurians. The quantity of phosphatic matter, indeed, is in places 
so considerable that it might be used profitably as a manure, if it were 
not so stronglj'- impregnated with pyrites. A good deal might be said 
about the history of these " bone-beds," f Vidiicli are known in other 
formations as well as the Lias, when similar conditions seem to have 
prevailed at distinct and widely distant intervals of time in the early 
history of our globe. In concluding the account of the Lias in 
Gloucestershire, we may, for one moment, carry our thoughts back to 
the state of the land and water during its deposition. The sea must 
Lave been highly charged with calcareous matter, usually making an 
* Fresh-water Crustacea inhabiting a bivalve shell. 
t A very probable view of the origin of tliese " bone beds " is given in " Stones 
of the Valley,'' page 18, an able ami interesting v/ork lately published by my 
li-iend, the Rev. W. S. Symonds, F.G.S., Hector of Feudoek.— P. B. li. 
