19 
effects of denudation in modifying the contour of the ground. The old 
city stands on low flat land, consisting mainly of new red sandstone ; the 
range of hills on the west and north-west, on which are built the 
suburbs of Clifton, Redland, Montpelier, Sotham, Kingsdown, &c, con- 
sists partly of the older carboniferous strata and partly of lias, which has 
escaped the denudation to which the foundation of the old city has been 
subjected. This exemption of the lias from the fate of its once continuous 
beds, seems to be greatly owing to its being backed by the harder and less 
yielding rocks of the carboniferous series, and partly to causes dependant 
upon the direction and comparative violence of currents in the seas, which 
affected the removal of so much solid matter from our neighbourhood' 
The great line of the denudation of the lias extends in a north-easterly 
direction from the city, and has an average breadth of about a mile. 
Skirting the lias at Asbley> and Montpelier, it forms an extensive bay 
sweeping round by Horfield, Redland, and White -ladies, to Gotham, there 
pursues its course in a wider channel, by the east side of the city, and 
curving round towards the south-west by Bedminster, expands into the 
great valley running by Ashton and Nailsea, to the moors, bordering the 
Bristol Channel. In the midst of this line of denudation are numerous 
masses of lias which have escaped the denuding influences, but which bear 
on their surface marks of the violent aqueous action to which they have 
been subjected. 
The Author concluded a long and interesting paper by a short reference 
to the topics of the Sequence of Geological Phenomena, and the Marks 
and Agencies of Denudation. 
ENTOMOLOGICAL SECTION. 
February 11th, 1868.— The President of the Section, Mr. S. 
Barton, in the chair. 
Mr. A. E. Hudd, exhibited a bred specimen of Cuculia gnaphii, an 
insect of extreme rarity in England. This specimen was bred from a larva 
taken at Tilgate, in 1866, by Mr. E. G. Meek; Mr. Hudd also showed a 
specimen of Acidulia rubricata, a rare species, a few examples of which 
have occurred from time to time on the South and South-eastern coasts. 
The President exhibited several splendid species of Anthophagus, 
a genus of foreign Coleoptera. 
Mr. J. W. Clarke (in the absence of the Hon. Secretary on account 
of indisposition), read a note on Vanessa levana, illustrated by specimens, 
