In December last Dr. C. A. White, Palæontologist to the U.S. Geological Survey, sent me a small packet of siliceous Ostracoda, obtained by dissolving in dilute acid some pieces of an impure limestone from the Jurassic “Atlantosaurus Beds” near Cañon City, Colorado. These strata are of freshwater origin; and, besides the wonderful Dinosaurian and Mammalian fauna, which Prof. O. C. Marsh has published, they contain, Dr. White informs me, Unio, Limnæa, Planorbis, and Valvata, all of modern types. In the impure limestone with Ostracods, and in associated layers, these Gasteropods are found also in a silicified state, and the Dinosaurian fossils occur both above and below them.

I am indebted to Thos. Parker, Esq., of Oldham, for the opportunity he has afforded me of examining his large collection of fish-remains from the Carboniferous Limestone of Derbyshire. The specimens have been obtained from quarries near Chapel-en-le-Frith, in the N.W. of the county. They are for the most part in a beautiful state of preservation, though some of the more fragile specimens are only obtained with the most careful manipulation on account of their liability to fracture. The fossils are creamy-white in a light-coloured crystalline limestone matrix.

One of the most important discoveries in Seismology is that which proved the close connexion in position between earthquakecentres and lines of fault, leading up to the view that the earthquake is an effect and not a cause of fault-formation. It may be the momentary result either (1) of the sudden fracturing of the earth's crust, or (2) of the impulsive friction that must accompany the relative displacement of the rock-masses adjoining the fissure. Now, earthquakes are frequent at places where faults are already advanced in the process of formation.

These works were at first only supplementary to the Lewes Road Works, on the east; but now are the chief source of supply. They were begun in 1865, and are placed in a hollow in the Chalk, in open ground. at the north-western edge of Brighton. This hollow, the bottom of which, I am told, is 30 feet below the lowest part of its rim, is perhaps in itself an evidence of the existence of underground water, being due, most likely, as is usually the case in limestone-districts, to the dissolving away of the rock by underground water and to the consequent sinking-in of the surface. It is an analogous occurrence to the Meres of Norfolk, except that these are generally more or less filled with water, whilst Goldstone Bottom is quite dry at the surface. I may mention that at the time of my visit there was so thick a fog that it was impossible to see the hollow.

The habits and distribution of this marine molluscan pest chiefly concern the engineer and ship-builder at the present day, but in the past their presence is a considerable guide to the geologist as to the conditions under which many of the Eocene beds were deposited. It does not seem to have existed in the Gault sea, for though the driftwood of this period is riddled by some of its destructive ancestors, such as Teredina, Lamarck, and perhaps Xylophaga, it is far less completely destroyed than when the true ship-worm has been at work. Something very like it is present in the Chalk; but when we come to the Eocenes, there is no longer any possibility of doubt as to the animal which has made its home in the drifting logs, for they are riddled in the way peculiar to the true ship-worm, and its shell is frequently left in the bore-holes