46 DAVIS : FISH-REMAINS IN THE COAL-MEASURES. 
inadequate if we imagine them to have been the denizens of 
a marine estuary, or even of a quickly flowing river. 
Higher in the series the black shale gives place to a 
whitish grey one, and the remains of the bivalves become 
much less frequent, and are only found preserved in the 
nodules of clay ironstone. Individual plant remains, reed- 
like in form and of large size, occur in abundance, their 
external part changed to a thin layer of bright glistening 
coal. The plants are always found laid horizontally, and never 
erect. They have evidently been conveyed by water to their 
present position. After the deposition of the shale with 
ironstone, the land re-emerged from the water, and a thick- 
ness of six feet of seat earth was formed, and on its surface a 
bed of coal of the ordinary kind. Then another submergence 
and deposition of 24 feet of shale, to be followed by a change 
of level, which again brought the land to the surface, and 
the Joan coal was accumulated. 
The following list of fossil remains have been found in 
the Stone-Coal and the " Hubb," mixed indiscriminately : — 
Ceelacanthus lepturus, Agass. 
Megalichthys Hibbertii, Agass. 
Ctenodus elegans, tooth. 
Rhizodopsis sp. ? 
Diplodus Gibbosus, teeth. 
Ctenoptychius, teeth. 
Palceoniscus (Elonichthys) Egertoni. 
Helodus simplex, Agass. 
Gyracanthus formosus, Agass. 
Cten acanthus hybodoides, Egerton. 
Two species not identified — spines. 
Bones of Labyrinthodont. 
Spiiorbis carbonarious. 
Entomostraca. 
Unios, or Anthracosia. 
In the West Riding, above many of the seams of coal at 
their junction with the shale, which usually succeeds next in 
