560 Geological Society. 
The mass of the two larger veins consists of dark green, crystallized 
hornblende, brownish red felspar, and occasionally quartz ; and re- 
gular transitions may be traced from syenite to greenstone. When 
viewed at a distance they present a rudely columnar structure. The 
centre vein contains much black hornblende, some black quartz, and 
presents a concretionary structure, the oval-shaped masses being en- 
veloped in a congeries of pinchbeck brown mica, A tendency to this 
structure is observable also in the upper vein. 
Owing to the covered nature of the ground, the syenite veins of the 
coast cannot be traced continuously to Torr Eskert, but by laying 
down the line of the veins of Goodland cliff on the Ordnance Map, 
and making due allowance for theit average inclination and the ele- 
vation of the hill, Mr. Griffith entertains no doubt that the syenite in 
the chalk of Torr Eskert is a prolongation of one of the syenite veins 
in the slate of the cliff. 
The syenite which traverses the chalk cannot be distinguished from 
that of the mica slate, and passes also in syenitic greenstone. At one 
point the author had a portion of the surface soil removed, and obtained 
the following section: 
Top... Compact chalk ..... i..57.,< erase Ee 
VERE). 6 gina oie ehoicts Rio. ein tials 5 — 
Chalk, irregular bed from 9 inches to 1 foot 
Wiiealate, .:icishit, wad aoacgielaste 
The lower bed of chalk contains quartz pebbles, green sand, and 
numerous, red, siliceous grains, some of which resemble garnets. The 
syenite presents large masses separated by chalk containing quartz- 
pebbles, green sand, and numerous fragments of fossils. These re- 
mains have nearly a vertical position when zn situ, and Mr. Griffith 
consequently infers that they are not in the position in which they 
were deposited. 
The irregularities on the surface of the chalk are accurately filled 
with the syenite: the chalk in immediate contact with the vein is 
usually compact, suinetimes crystallized ; and pebbles of quartz si- 
milar to those in the green sand and chalk are found occasionally in 
the syenite. The author noticed a small reniform mass of syenite 
imbedded in the chalk—the grain of the included portion being finer 
than that of the syenite in general. Small particles of chalk were 
likewise noticed in the syenite, and the union of the two rocks is so 
perfect that the chalk appears to be an integral portion of a compound 
deposit. Among other peculiarities exhibited at the junctionof the two 
formations, the author mentions spheroidal masses of syenite in- 
cludedin the chalk ; and, in conclusion, he says, that if the views which 
he has put forward have been substantiated, a new and important fact 
is added to those already described, which may ultimately lead us to 
attribute a comparatively recent origin not only to syenite veins and 
primary greenstone, but also to crystalline rocks generally when as- 
sociated with schistose strata. 
A letter from H. T. De la Beche, Esq., addressed to the President, 
and dated Truro, the 18th of December, 1835, was then read. 
This letter was accompanied by a collection of fossils from the 
