432 W. J. SOLLAS ON THE SILURIAN DISTRICT 
stone thus presents a prevailing reddish tint when the red oxide is 
abundant; but on minute inspection it is seen to be really greyish 
or colourless, and only speckled with red dots. ‘This gives it a very 
characteristic appearance ; and as it is the only bed traceable across 
the country, we may conveniently give it a distinct name, the 
«Rhymney Grit” appearing to be the most appropriate. 
Mr. Storrie, the Curator of the Cardiff Museum, has prepared some 
thin slices from one of the sandstone beds which contains fragments 
of mineral charcoal; and these show under the microscope very 
distinct woody structure. This fact, combined with the leaf-like 
form of many of the fragments and the spore-like structure of others, 
leads us to imagine that we have in this mineral charcoal the earliest 
known occurrence of terrestrial plant-remains in the Silurian series 
of Europe. . 
The fossils in the yellow sandstone, or “‘ Ctenodonta-bed,” whic 
occurs in a recess of the quarry near the top on the north side, are 
only found as casts. They are very abundant, well defined, and 
would repay a more extended examination than I have yet been 
able to give them. 
The following is a list of Mr. Etheridge’s determinations, to which 
I have ventured to add one or two of my own making :— 
List of Fossils from the Ctenodonta-bed, Rhymney Quarry. 
Llan- 
d Wenlock. | Ludlow. 
overy. 
Ctenodonta subzequalis, Sow. ............ * 
Modiolopsis platyphylla, Saléer 
elevata, Sollas. 
acutiprora, Sol/as. 
Modiola, sp. 
Holopella gracilior, M‘Coy............2.) 0 veeeee * 
—— hydropica, Sod/as. 
minuta, Sollas. 
Murchisonia gracilis, Hall. Llandeilo. 
—— elegans, Sollas. 
Pterinea pleuroptera, Conr. Caradoc. 
——, sp. 
Bellerophon carinatus, Sow. ............ * 
Cyrtoceras, sp. 
Rhynchonella nucula, Sow................ * * 
IDNigerine, rane, YOR, cgasoaonaceacpocn00a0]] — o0a00 x 
Sjomeodots IDAs, WNC  gosoouconcacoeanea| | Ob0004 x ar 
Polyzoon. 
Fragments of plants, including Pachy- 
theca spherica, Hooker .................. 
* 
An examination of this list appears to indicate Ludlow rather 
than Llandovery affinities, and thus led me to look for the appearance 
of the Rhymney Grit near the top of the river-section below Cae 
Castell. It was therefore with some surprise that, failing to find it 
there, I afterwards discovered it near the base of that section. This 
opservation, however, cleared up the difficulties which the country 
