A not uncommon fossil of the Chalk, in both the upper and lower divisions, is an elongated, and more or less undulating body, composed of the scales and bones of fishes confusedly mingled one with another, and known to the quarrymen as “Petrified Eels.” Dr. Mantell was the first to discover and describe these singular objects; he says, “A long cylindrical fish, of which neither the fins nor the extremities have been discovered, is one of the most frequent, but most imperfect of the Sussex ichthyolites. The specimens are of a subcylindrical form, rather flattened by compression, from six inches to two feet in length, and about one inch wide. They occur abundantly in the Upper Chalk, and occasionally in the siliceous nodules. They are, for the most part, perfectly straight; but some specimens are undulated, as if the fish had been suddenly enveloped in the Chalk while in a state of motion. The surface is covered with small delicate smooth scales, confusedly mixed together; not one instance having been noticed in which they are disposed with any degree of regularity.”

In the spring of the year 1878 I brought under the notice of the Geological Society a paper describing for the first time as Marine, the Upper Series of the Bournemouth strata, present in thickness to the east of Bournemouth Pier. The publication has been delayed, but the present sketch will only to a very slight extent forestall it, and is written simply with a view to make clear the synchrony of the Bournemouth Marine Beds with the lower part of the Bracklesham Beds of the Hampshire Basin, the Middle and so-called Upper Bagshot Beds of the London Basin, and the Bovey Tracey Beds, the true position of the latter, especially, being more clear at the present moment than it was a few months ago. I propose first to describe briefly the Bournemouth Marine Strata, and then the other formations with which I have correlated them, in the order in which they are mentioned above.

The rocks I propose to describe in this paper belong to that great metamorphic series which occupies so large a portion of the north of Ireland, extending over most of the counties Tyrone, Londonderry, and Donegal. For the present I shall confine, my observations principally to that portion of them situated about the central parts of Tyrone, from the vicinity of Omagh eastwards and north-eastwards towards Slieve Gallion. This district has “Geological Report on Londonderry and parts of Tyrone and Fermanagh”; but as, during the progress of my work for the Geological Survey, I have had opportunities for a very detailed examination of it, I beg, briefly, to offer some further remarks and conclusions.

BY far the larger proportion of the Carboniferous fossils described and figured by the late Professor John Phillips, F.R.S., in the second volume of his “Illustrations of the Geology of Yorkshire,” and published in 1836, are contained in the collection of the late Mr. Gilbertson, of Clitheroe, now deposited in the Geological Department of the British Museum. The early date of publication of this work renders the collection described in it one of the most important, next to those of Sowerby, Ure, Martin, and one or two others, to students not only of British, but equally so of Continental Carboniferous Palæontology. Unfortunately the descriptions of Prof. Phillips are so abbreviated and unsatisfactory, and the figures in many instances so mearge, that it is with great difficulty anything like an accurate determination of a species can be made by the aid of them. Under these circumstances the following notes made directly from the type specimens will probably be found of use; it would, however, be far more satisfactory to have the specimens refigured. For convenience sake I shall commence with those composing plate vi., and then take the others composing plate v.

The following observations of the Cornish Cliffs are given in order, proceeding round the coast from Plymouth. The numbers and letters have been prefixed to facilitate subsequent reference.