358 Proceedings of the Royal Society 
Besides the one-inch maps, however, there have been published 
detailed maps on the scale of six inches to a mile of the coal-fields 
of Edinburgh, Haddington, and part of Fife, and it is intended to 
continue the series through the other coal-hasins. Horizontal sec- 
tions, on the same large scale, have likewise been issued ; one of 
these stretches from Edinburgh, through Arthur Seat and the 
G-arlton Hills, to the coast near Dunbar ; two others cross Mid- 
Lothian to the Lammermuir Hills, showing the structure of the 
Pentland Hills and of the Edinburgh coal-field. Descriptive 
memoirs of the neighbourhood of Edinburgh and of the East of 
Berwickshire have been published to illustrate sheets 32 and 34 of 
the geological map, and others of Fife and East Lothian are in 
preparation. A large collection of specimens of the rocks and 
fossils of the Lothians, Fife, and the south-west of Ayrshire has 
been made in duplicate, one series being deposited in the Industrial 
Museum, Edinburgh, the other in the Museum of the G-eological 
Survey, London. 
Among the scientific results of the survey, by which fresh light 
has been thrown on the geological structure of Scotland, mention 
may be made of the discovery of well-marked graptolites (Grapto- 
litJius priodon and Diplograpsus pristis) among the Silurian rocks 
of the Lammermuir chain, shewing that these strata are probably 
the equivalents of the Llandeilo and Caradoc formations of Wales. 
A considerable addition has likewise been made to the known list 
of fossils from the lower Silurian limestones and shales of Peebles- 
shire, while in Ayrshire, a large suite of shells, trilobites, corals, 
and other organic remains, has recently been made from the lower 
and upper Silurian rocks, and is now under examination in the 
Museum, Jermyn Street. The discovery of a numerous group of 
well-preserved fossils in the shales and mudstones of the Pentland 
Hills proved these strata to be of the age of the Ludlow rocks, a 
position much higher than had before been given to them. 
In the Old Bed Sandstone, much interesting work has been 
accomplished. It has been ascertained that this formation in the 
Lowlands of Scotland is capable of subdivision into three zones. 
The lowest of these is well seen between Tinto and the confines of 
Ayrshire. It merges into the upper Silurian shales of Lesma- 
hagow, and is covered unconformably by all later rocks. In the 
