King and Rowney— On Serpentine Marble or OpJiite of Sky e. 133 
are of a doubtful nature, appearing more or less like amorphous 
amphibolic matter, or imperfectly developed serpentine. Calcareous 
layers, faintly crystalline, and containing flattened pieces of a dark 
green serpentine-like substance, are present in some parts of the 
marble. 
Want of time prevented any observations being made with the 
object of determining the relation between the afore-mentioned siliceous 
minerals and the augitic greenstone" of the dykes that cut through 
the marble.^ Serpentine, according to the highest authorities, is con- 
sidered to be in all cases a pseudomorph. Such we assume to be the 
case with the green streaks " of this mineral, which," accordiag 
to Geikie, mottle the marble where it is intersected by trap dykes;" 
and hence they may be pseudomorphic after the ''augitic greenstone." 
The junction between the syenite and the marble is not ill- 
defined ; but no veins were observed carrying the one into the other. 
The contact surfaces are rugged, with irregular projections and 
hollows. 
The beds adjacent to the marble are calcareous, have a blue 
greyish colour, and contain numerous white irregularly-shaped siliceous 
concretion-like bodies ; which, as suggested by MaccuUoch and Geikie, 
may possibly be fossil remains that have lost all traces of organic 
structure through semi-metamorphism. 
JS'ext follows a considerable thickness of hard limestones : some 
blackish-grey, with thin irregular laminae of sandy argillaceous 
matter ; others of a lighter colour, largely composed of minute siliceous 
particles, apparently sand. Some of the beds contain numerous minute 
spheroidal bodies, which, when sections are examined with an ordinary 
magnifier, show nothing more than the appearances peculiar to oolitic 
grains. At first sight the more spherical forms might be taken for 
fossil Orbulinas ; but, as they completely fail in showing any shell- 
structures, their foraminiferal nature is rendered doubtful. There are 
also numerous small pieces with the characteristic cleavage of calcite ; 
many of which appear to be of crystalline origin ; but some, we have 
no doubt, are fragments of Encrinites. Possibly it was in some of the 
limestones under consideration that Mr. Geikie found ''what appeared 
to be fragments of a Pentacrinite." Be this as it may, true fossils do 
occur in the whole series ; since we have detected with a common 
lens shells of Foraminifera in abundance. We have also observed a few 
cylindrical bodies, longitudinally fluted, and somewhat thicker than a 
pin : examined with a higher power, transverse sections of the latter 
show them to possess internally a radial structure ; the ribs corres- 
ponding to the radii ; which is suggestive of their being the remains 
of minute echinidial spines. There are likewise present numerous 
fragments of very small bivalve and univalve shells. In the same 
series of beds was also found the complete rim of a concave calice of 
* Geikie, "Quarterly Journal of the Geological Society:" vol. xiv., p. 19. 
