Extracts from the Minute Book of the Geological Society . 623 
At Mill Bay, behind the coke-kiln, madrepores are abundant from 
the surface to the lowest part of the rock that can be seen. 
Not far from Sandy Cove, upon the east Hoe, nearly under the 
citadel, I have obtained shells that are all univalves. In texture 
they are close-grained, hard, compact, and of the colour and sub- 
stance of the surrounding matter, much resembling in their appear- 
ance those from Stonehouse-hill. 
Immediately on crossing the water from the Victualling-office 
point, adjoining the citadel, to Tate’s Hill and Queen Anne’s Bat- 
tery, an abundance of animal remains, although no shells, appear, 
particularly at the latter place. At Queen Anne’s Battery, besides 
entrochi and many varieties of madrepores, I have observed what I 
conceive may be an alcyonium. 
At a little distance from hence, in Headman’s Bay, near the 
quarry, madrepores, tubipores, and bivalve shells, with other organic 
remains are to be seen ; and in a quarry on the opposite side of 
Catdown, across the road to the eastward, madrepores, tubipores, 
and univalve shells are found. Advancing still to the eastward as 
far as Prince rock and the Flying bridge, I there find entrochi, ma- 
drepores, and a fossil, of which I have collected fine specimens, and 
which I believe to be an orthoceratite. 
Thus from the Tamar to the Plym, over a distance of nearly 
three miles, animal remains pervade the whole bed of the Plymouth 
limestone. 
With regard to metallic veins, the limestone appears to be en- 
tirely free from them ; for I have never heard that any symptoms 
of one were ever discovered in any of the quarries that have hitherto 
been opened. Indications of the presence of iron and manganese 
may occasionally be detected, serving as colouring matter, in parti- 
cular spots ; but these metals are always thinly spread, and are never 
Vol. V. 4 k 
