I must refer to Memoir No. 1—Corallian Gasteropoda—for remarks with respect to the so-called Chemnitzias. The curious group, of which “Terebra vetusta,” Phil., may be regarded as the type, is also very doubtfully placed under Chemnitzia.

In Cardiganshire and the neighbouring counties of Central Wales there are abundant traces of the action of the great accumulations of ice and snow which covered all the mountains of Britain in the Glacial period. in the valleys lie thick sheets of Till and morainic formations, the hill sides are rounded and polished by the friction of the moving ice, and erratic blocks are strewn in abundance over hill and valley throughout the district.

Earthquake-shocks have generally been divided into three classes:

a. Undulatory shocks, by far the most commonly felt, consisting of one or several waves, the movement at any place being to and fro along a line inclined to the horizon, but in general nearly horizontal.

b. “Sussultatore” shocks, consisting of one or more up-and-down movements, in a nearly vertical direction.

On removing the superficial sand and soil to prepare for getting clay for brick-making, it is not unusual to find the surface of the Boulder-clay in this neighbourhood corrugated with tortuous channels. These channels are commonly filled with slutchy sand and gravel, which must be removed before the clay can be obtained.

At the present time there is an excellent example to be seen in Earle Eoad, Smithdown Road, Liverpool, next to the site of a new Board School that I am, as architect, superintending. The surface of the ground slopes rather quickly to the valley below, and the superficial strata consist of soil and a yellow subaërial quartzose sand, together from 4 to 5 feet deep, in which there are no stones or gravel. This sand we are using for mortar, it being what is called “sharp,” or consisting of angular grains. Below this the corrugations of the Boulder-clay are better developed than I have seen elsewhere, and give a clue to the origin of these channel-like depressions.

If we now turn further east to Belgium and its borders, we shall find the same conclusion arrived at by inquirers. In the admirable memoir of M. d'Acy, already named, entitled “Limon des Plateaux du Nord de la France,” the author has examined in great detail and with care the composition of the loamy mantle that overspreads the other surface deposits of Belgium and Picardy. His sections and descriptions show very clearly how its texture, passing from coarse materials in its bottom layers and gradually getting finer and more pulverulent in its upper ones, is such as we should expect from the effect of gravitation acting upon great masses of mud, etc., borne along by a rapid flood.

Any geologist who has spent a short time at Eisenach, and has examined any of the numerous road- and hill-side sections in the district about the celebrated Wartburg, must have been struck, as I was myself several years ago, with the enormous development of the breccias and conglomerates interbedded with well-stratified sandstones and marls; and this district is fairly typical of the Thüringerwald. For an account of these the reader must be referred to Siluria, to the paper by Murchison and Morris before mentioned, and to Credner. The former writers remark: “The movements by which the great brecciated masses were aggregated were clearly suspended and repeated many times; the intervals of quiescence allowing of those deposits of finely, triturated red sand and marl which alternate with the coarse and subangular conglomerates. … These breccias and conglomerates, with their associated sandstones, are of gigantic dimensions, and have been bored into in fruitless searches after coal to a depth of about 2500 English feet.” (Here is surely something more than a mere appendage to the Carboniferous.)