870 
THE GEOLOGIST. 
is further increased by the numerous hoforo-mentionod bays jutting into 
the limestone. In addition to this, over the country extending from the 
outburst of the limestone to the sea, the large fissures already spoken of 
as intersecting in all directions the limestone form so many channels of 
communication between the surface and the bed of " yellow sand" down 
■which the surface drainage, and even in some instances small streams, pass 
freely. It cannot therefore be wondered at that, when this formation is 
pierced by any shaft below the level of saturation, large volumes of water 
should be encountered ; and, although this may for the time increase the 
engineering difBculties, and frequently add much to the cost of winning 
coal through the limestone, it has at the same time its brighter points of 
view, affording, as it does, an inexhaustible supply of pure and agreeable 
water to the inhabitants residing on its surface. The large towns of South 
Shields and Sunderland are entirely supplied by water pumped at exten- 
sive works at Cleadon, Yulwell, and Humbledon Hill. The town of Sea- 
ham Harbour is also similarly supplied. The water is hard for domestic 
purposes, but delightfully clear and refreshing to the taste." The general 
stratigraphical character of the magnesian limestone of the district was 
then entered upon. The next subject was the connection between the dis- 
location affecting the coal-measures and the magnesian limestone, this 
portion of the paper being illustrated by reference to a forty-feet upthrow 
fault, which passes through both the "Jane" and " Caroline" shafts of the 
Eppleton Hetton Colliery. 
Skiddaw-Slate Fossils, and Hoenblexdic Greenstones and their 
Eelations to the Metaiioephic and Silueian Eocks of the County 
OF Tteone. By Professor Harkness. 
New Coal-Plants feom Nova Scotia. By Dr. Dawson. — One of the 
plants, L. Acadianus, belonged to the genus Lepidojpliloios of Sternberg; 
the other was an example of a type of Lepidodendron, very characteristic, 
in Nova Scotia, of the lower coal-measures associated with the lower car- 
boniferous limestone. The author concluded that the original species of 
Sternberg, L. laricinum, was founded on the fragment of the bark of an 
old trunk, having the leaf-bases flattened, and hence described as scales. 
It was evidently, in short, closely allied to the specimen described. The 
genus Ulodendron was, he thought, identical with Lepidophloios, but ap- 
parently founded on specimens having the leaf-bases preserved, with the 
cone scars, but wanting vascular scars. It appeared to him that the ge- 
neric names Ulodendron, Lomatophloios, Leptoxylum, Pachyphlceus, and 
Bothrodendron should be abolished in favour of Lepidophloios, unless in- 
deed it should appear that any of these names had priority in date. The 
second plant described was the Lepidodendron corru(jatnm, \Ahich was 
one of the most abundant in the lower coal-measures of Nova Scotia and 
New Brunswick. The species was remarkable for its variability, and also 
for the dissimilar appearances of old stems and branches occasioned by the 
separation of the areoles in the growth of the bark, instead of the areoles 
themselves increasing in size, as in some other Lepidodendra, 
Models illusteating the Contoetions in Mica-Schist and Slate. 
By Mr. H. C. Sorby. — The models consisted simply of bands of india-rub- 
ber laid upon each other. In one, the alternate bands were covered with 
cloth, so as to deprive them of the elasticity possessed by pure india-rub- 
ber. The object of the models was to show how various phenomena in 
nature have probably been caused by lateral or superincumbent pressure. 
Pressing each end of a model with a little force, Mr. Sorby easily produced 
a series of curves and undulations, the suggestions of which were at once 
appreciated by the Section. In the case of the model with the alternate 
