The discussion on Mr. Boyd Dawkins's paper, “ On the age of the Lower Brick-earths of the Thames valley,” at the meeting of the Geological Society of London, 9th of January, induces me to submit a view of the relative ages of the Boulder-clays of the east of England, which seems to bring into harmony the views of Mr. Dawkins, and the physical evidence suggested in the discussion that seemed to conflict with them.

Mr. Dawkins' opinion that the lower deposits of Brick-earth at Grays' Thurrock, Crayford, and Erith were super-imposed by a Glacial deposit containing transported materials, was objected to on the grounds that they occur in a valley apparently excavated after the deposition of the Boulder-clay capping the high land to the north of London—implying an interval between the Muswell Hill Boulder-clay, and the supposed Glacial deposits of the Thames Valley, represented by the entire excavation of the valley, and the deposition of the Brick-earths and gravels, containing mammalian remains, underlying the Glacial beds.

Two of the Gymnospermatous Orders are represented by fruits found in Secondary strata, viz., Cycadeœ and Coniferœ; no remains have been observed, as far as I know of any plant belonging to the Gnetaceœ.. There is satisfactory evidence of the existence of Coniferœ from the period of the Old Red Sandstone; but it is very doubtful whether the Palæozoic fruits and leaves which have been referred to Cycadeœ have anything whatever to do with that order.

The recent deplorable explosions in the Barnsley and North Staffordshire Coal Fields have again called attention to the coincidence of such terrible accidents with a sudden fall of the barometer, by which they are so frequently preceded, suggesting the idea that they may be to some extent connected as cause and effect, and perhaps the following facts may induce a belief that there is truth in the supposition.

Some years since (in 1848) my attention was called to a well at Whittingham, on a farm then and now occupied by Mr. John France, about four miles N. W. of Preston, in Lancashire, celebrated in the district as “the blowing well.” This well was sunk for the purpose of supplying the farm buildings with water, but after going down about eighty feet in vain, the work was abandoned, and the well was covered with a large flagstone, with a hole through it for the chain used in placing it on the well.

The Lower Silurian Rocks of the South of Scotland, below the level of the Wrae Limestone of Peeblesshire, though of great thickness, and little altered by igneous agency, have as yet yielded but few of the higher forms of animal life. Two species of a phyllopod crustacean, (Peltocaris aptychoides and P. Harknessi, Salter), were discovered by Prof. Harkness, along with the first Brachiopod found in these deposits, the Siphonotreta micula of McCoy. Another crustacean of an allied genus, described by Mr. Henry Woodward, and named by him Discinocaris Browniana, was discovered last year in the neighbourhood of Moffat, by Mr. D. J. Brown. Besides the above, there occur traces of the action of marine worms, and I have, in addition, found one, possibly two, species of Lingula, a thin-walled Orthoceras, or Pteropod, and some curious spine-like bodies, probably referable to crustaceans. With the exception of these scanty remains, the strata under consideration have yielded no fossils higher in the scale of existence than Graptolites. In no other British deposit do we, however, find a greater profusion of these beautiful and characteristic fossils, or a greater number of specific types. It is the object of this communication to describe certain new forms of Graptolites which have come under my notice, together with one remarkable genus, apparently allied to the Graptolitidœ, though probably representing a different order.

The lower strata of the Silurian system are, as yet, but little known. The labours of Welsh and other geologists have brought to light the large fauna of the Lingula flags; but while the Upper Cambrian has thus been established and elucidated, the beds which lie immediately above it, namely the “Arenig group,” and the Llandeilo flags, remain to be searched, and a great part of the respective fauna of each to be described.

The Areing, or Skiddaw, group of Sedwick forms the base of the true Silurian rocks; it immediately underlies the Llandeilo flags, from which it is totally distinct, although caused with them in Murchison's “Siluria.”