1817.] Linnean Society. 395 
of serpent found in Dorsetshire, and long ago described by Linneeus, 
was given by Mr. Rackett. It is more poisonous than the common 
viper. 
At the same meeting a paper by Mr. Colebrook was read, de- 
scribing some little known Indian plants. 
GEOLOGICAL SOCIETY. 
June 21.—A paper by Dr. Clarke on the Composition of a dark 
‘ bituminous Lime-stone from the Parish of Whiteford, in Flint- 
shire, was read. 
The lime-stone in question is remarkable for making with the 
usual ingredients an excellent water cement. It appears from Dr. 
Clarke’s analysis to consist of about 90 per cent. of carbonate of 
lime, the remainder being chiefly alumine, with minute portions of 
silex and bitumen. 
A letter from Robert Anstie, Esq. of Bridgewater, was read. 
This letter, with illustrative drawings, describes some fossil ver- 
tebree, ribs, and scapula, of a large animal, probably of the genus 
lacuta, which have lately been discovered imbedded in lias lime- 
stone, near Kingsdon, between Somerton and Ilchester. It also 
describes a fossil fish, apparently of the genus clupea, which was 
found imbedded in lyas at East Quantock Head, in the Bristol 
Channel. . 
A paper on Magnesian Lime-stone by Hen. Warburton, Esq. 
V.P.G.S. was read. 
The largest continuous deposit of magnesian lime-stone extends 
from Sunderland to the vicinity of Nottingham, where it suddenly 
terminates. It is disposed in horizontal beds lying conformably with 
the red marl by which it is generally covered, and with which it 
sometimes alternates. It is represented as covering part of the coal 
measures ; but whether it lies conformable with these latter has not 
been ascertained. 
The red marl is widely distributed along the tract of country 
which lies between Lancashire and the southern coast of Devon- 
shire, lying horizontally, as in the North of England, on the in- 
clined beds of the coal measures, and bounding them at their 
basset. In this red marl, beds of a breccia, the cement of which is 
magnesian carbonate of lime, have been observed by Dr. Bright at 
Kingswood, near Bristol; by Dr. Wollaston and Mr. Greenough 
at Cowbridge, in South Wales; and by Mr. Aikin at Caerdeston 
and Loton, in Shropshire. Insulated blocks of a similar rock have 
been observed by Mr. Warburton and the late Mr. Tennant incum- 
bent on the lime-stone on the Mendip Hills, near Cheddar. 
The relation between the red marl and the coal measures it is of 
great importance to have thoroughly ascertained. If the former be 
considered as one of the complete series of beds which succeed each 
other in an invariable order, then we might expect, by sinking 
through the red marl in any place, to arrive at coal; but if, on the 
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