BEVAN — ON THE SOUTH WALES COAL-FIELD. 
97 
at Aborsychan, Vartog, and Blanafon works. At Varteg, the coal 
thickens out to an aggregate of fifty-one feet, the Rock-vein, wliich 
is hero called the " Droydeg"-vein, tliinning to six feet five inches, 
and the Meadow-vein increasing to seven feet. At Blanafon the 
former is called the " Bydellog"-coal, a name which it keeps until we 
enter Glamorganshire ; wliile the latter is the equivalent of either the 
Pwltacea, or the old-coal, most likely of the first. 
Hero we tm-n the comer of the basin, and proceed eastward, the 
measures rounding the Ganerew mountain into the Clydach valley. 
Of this beautiful dingle I need only mention that the scenery will 
amply repay any visitor, being equal to many parts of Derbyshire. 
Here, too, were the fii'st specimens of the Stigmaria observed and 
described by that intelligent old philosopher Lhwyd. Good coal- 
plants can be easily obtained at all these works at the expense of a 
little trouble, though it is always as well to apply first of all to the 
■underground agents, who are generally glad to afford information. 
The valleys of the Ebbw having been already described in the 
" Geologist," vol. i., p. 119-124, I need not touch upon them any 
further, but pass at once through Nantygls, Beaufort, and Tredegan 
into the Rhymney-valley, Along the whole of the road good 
Bections of the bottom-veins are constantly to be met with, and in 
many of the " tips" are plenty of fish-remains and Antliracosias 
(principally A. agrcstis). 
Above Rhyrnney Gate, in the bed of the river, is the most prolific 
fiheU-bed that can be imagined, lying in the " Fareweir'-rock, just 
above the millstone-grit. This is the horizon of the marine shell- 
bed which runs from Beaufort into Camarthenshire. The principal 
veins worked at Rhyrnney are — 
EUed 
Ft. in. 
. 4 0 
Equivalent to the three- ") 
quarter coal of Nan- > Upper Four-foot 
tygls and Ebbw-vale. ) 
Big Vein,., 
Equivalent to the Droy- ^ 
4 10 
3 
1 
5 
8 
Thee coals 
2 
4 
vol,. III. 
