MARBLES. 
23". 
Staffordshire ; whilst the fossiliferous limestones of the Devonian 
system — still older than those of the Carboniferous series — yield 
the valuable marbles of South Devon. 
Derbyshire Marbles. — Pilaster, 136. Columns, dc., JS T os. 31, 
47, 57, 58, 65, 68, 69, 93, 94, 96, 97, 108, 110, 113, 118, 
122, 124, 125, 135, 138 141, 156, 168, 173, and 192. 
Tazze, &c., JS r os. 66, 70, 74, 80, 107, 109, 121, 123, 187, and 
189. Inlaid Work, JS r os. 145 and 161. Cubes in Case I. 
The rocks of Derbyshire are rich in ornamental marbles, 
which, from their beauty, and in many respects their curious 
characters, have been largely employed for decorative purposes. 
They are usually distinguished by their colour — as grey, dove,, 
black, rosewood, and russet marbles ; or by physical peculiari- 
ties, dependent mostly upon their fossil contents, as bird’s- 
eye, dog-tooth or mussel, entrochal, coral, shelly, and breccia 
marbles. The limestone of Derbyshire forms a very thick mass 
divided by thin partings of shale, and by the igneous rocks called 
toadstone — said to be a corruption of the German Todtstein, 
or “ dead stone,” in allusion to these trap rocks being usually 
barren of lead ore compared with the adjacent limestones. The 
toadstone consists of doleritic and basaltic lavas, in some places 
amygdaloidal and often more or less altered into diabase, and 
associated locally with volcanic tuffs. 
Among the ornamental marbles of Derbyshire is the well- 
known crinoidal or encrinital marble, so called from the pre- 
sence of abundant fossil remains of encrinites, or “ stone lilies.” 
These were echinoderms belonging to the Crinoidea — a group 
of which there were formerly but few living representatives 
known, compared with the abundance which existed in the 
Palaeozoic and Secondary periods. The beautifully-formed 
and numerously-jointed Pentacrinus capuUMedusce, which is 
occasionally dredged from great depths near the West India 
Islands, is one of the finest living examples of this class ; but a 
rich diversity of forms has been discovered in recent years by 
the Challenger and other exploring expeditions. The encrinite 
consisted of a long jointed column attached by one extremity 
to the sea-bottom, and supporting at the opposite .extremity a 
cup-shaped body, from which radiated several articulated arms 
furnished with ciliated appendages. The entire structure 
was rendered flexible by the internal calcareous skeleton 
being composed of numerous bead -like joints. The dislocated 
fragments, or joints, are cemented together, in the marble, 
by means of carbonate of lime ; and being, in the process of 
manufacture, cut in many different -direct ions, assume a variety 
of forms. Many beautiful examples of these crinoid marbles 
will be found in the collection. The perforations in the 
centre of the joints afford facilities for stringing them as 
beads; in this way these fossils were used as rosaries, and they 
are still known in northern England as ‘ St. Cuthbert’s beads.” 
