Most of the recent advances in the knowledge of trilobitestructure have come from the study of Triarthrus. Since Valiant's discovery of the antennæ, and its announcement by Matthew in 1893, the writer has published a series of papers on the detailed structure of this trilobite. Much time has also been spent in carefully working out the numerous specimens from the abundant material in the Yale Museum. Altogether upwards of five hundred individuals with appendages more or less complete have been investigated; and at the present time, it may safely be said that the important exoskeletal features have been seen and described.

Some molluscan and other remains obtained by Miss Forbes and Miss Lowndes from a brick-pit exposure at Okeford Fitzpaine, near Shillingstone station, Dorsetshire, have recently been submitted to me for determination. They comprise two series of specimens indicative of the well-known Cretaceous zones of Acanthoceras mammillatum and Hoplites interruptus. Those from the former or earlier horizon were collected about nine years ago, whereas the others were obtained within the last few weeks. It will be convenient to name the species identified from the Acanthoceras mammillatum zone first, then to describe the beds constituting the whole of the section, and lastly to give a list of the fauna from the Hoplites interruptus zone.

In August, 1891, I published in the Geological Magazine the results of my work on the Pleistocene beds of Gozo. Since then I have made a careful and systematic survey of the islands, and have discovered and traced out several important beds that had escaped the notice of those who had preceded me in working out the islands' geology. In the following “notes” I have briefly summarized the results in the hope that they may be of use, not only to other students of the geology of the district, but also to the agriculturist, who, by drawing on the resources that they offer, may bring into cultivation much of that portion of the western parts of the islands which from its supposed dearth of soil has hitherto been looked upon as uncultivable. I have elsewhere described this district and its capabilities; there is, therefore, no need for me to enlarge upon that part of the subject here.

I Have not been able to trace the exact relationships of this zone, with its bands of limestone, to those already given, as underlying it. Certain grits and quartzites occurring on the top of the Ben Lawers ridge may possibly belong to it, and it is certain that many of the quartzites and grits of Glenlyon, Blair Athole, and Ben Y Ghloe belong to a horizon higher than the upper argillaceous series just described. Leaving the matter thus in the meantime, until further research shall explain their true relationship, it is certain that an arenaceous band of grits and quartzites succeeds the sericite and graphite schists of the upper argillaceous zone, thus completing the whole cycle of deposits, though no evidence has yet been forthcoming to show what or where the top of this series may be.

However paradoxical it may appear, we have reason to believe that the occurrence of so-called ganoidian fishes—of a freshwater type—in the Old Red Sandstone affords the strongest evidence in favour of its marine origin. That recent representatives of the ganoids of the Old Red Sandstone inhabit rivers and lakes of the globe, is by no means a proof of the fresh-water origin of the latter fishes. The immense interval of time implied by the comparison renders its value somewhat problematical. Sir A. Geikie, in referring to the fishes of the Old Red Sandstone, says: “That some of the fishes found their way to the sea, as our modern salmon does, is indicated by the occasional occurrence of their remains among those of the truly marine fauna of the Devonian rocks.”

In the Transactions of the Edinburgh Geological Society (vol. v, p. 316) will be found a notice of a section at Lochrim Burn, a quarter of a mile south of Corrie, where is exposed a bed of red sandy shale containing marine fossils. The catalogue contains fifteen species (certified by Mr. John Young, LL.D.), and every one of these is common in the Carboniferous Limestone series of the West of Scotland. This bed is overlain by another bed containing abundant plant-remains, of which a list of seven species is given. The Rev. D. Landsborough, of Kilmarnock, found here another, viz. Carpolithes sulcatus, L. and H. (“Fossil Flora,” pl. ccxx), which Mr. Kidston considers to be characteristic of the Calciferous Sandstone series. It seems to me, however, that the evidence is rather in favour of these beds belonging to the Limestone series. Then, as already noted, there are the fireclays, of which I have observed several distinct beds along the Corrie shore. There is also a bed of fireclay in the old quarry behind Corrie Hotel (within 100 feet of the Productus giganteus limestone); this overlies a bed of fine white sandstone. Fireclays also occur in the gap between the northern and the great eastern cliff.