On the occurrence of Calcisyhera 
(@illiamson) in the Mountain Limestone of 
the Lgltovseg Rocks, near Llangollen, 
BY GEORGE W. SHRUBSOLE. 
Read December 2nd, 1880. 
N the summer of 1878, when in the neigbourhood of Mold, 
Flintshire, I observed by the road side a heap of limestone, 
which, by its colour and appearance, attracted my attention. 
It was a fine grained stone, dark in colour, and thickly studded 
with minute spherical bodies which, from their size and white- 
ness, gave a slightly mottled appearance to the stone. The 
nature of these bodies was somewhat puzzling. Foraminiferal 
and Radiolarian origin were both suggested. With the view of 
securing additional information, fragments of the stone were 
freely distributed, among others to Pror. W. C. WILLIAMSON, 
F.R.S., by Mr. J. D. Smppatt, with the result that he has 
described in the Philosophical Transactions,* under the head of 
Calcisphera, six species of some early form of life. Meanwhile 
the source of the fragments which contained Calcisphera was 
unknown, beyond the fact that they were obtained in a mountain 
limestone country. In the course of last summer I found among 
the talus at the base of the Eglwyseg Rocks, near Llangollen, 
a stone identical with the former from near Mold. Sub- 
sequently I found the same rock 7” sz#u some 50 yards higher 
up, and traced Calcisphera through some 20 feet of exposed 
limestone rock. I do not think that it is limited even to this 
area, but there were no facilities for further exploration. I have 
seen indications which lead me to think, that Calcsphera will 
be found widely distributed in certain divisions of the limestone. 
I found this limestone used as road metal in the town of Rhyl. 
Mr. ARTHUR ACTON informs me that he has traced it for 
several miles along the outcrop of the’ lower beds, whenever 
exposed, at the base of the Eglwyseg Rocks. It may be taken 
as a fact that Calc’sphera is characteristic of, and a leading 
constituent in, many of the bands of limestone which comprise 
the lowest series in the lower or basement beds of North Wales. 
* Trans. Roy. Soc., p. 520, Part II., 1880. 
