The specimens here described were obtained by the writer from a pocket in the surface of the Silurian Slates about 200 yards to the north of Gillet Brae, exposed during the preliminary excavation for Mr. Delany's quarry (the Horton Lime Works) in 1889. The quarry is situated on the right bank of the Ribble, opposite Horton village. The site of the exposure is now buried under tip heaps and there is little chance of further sections being exposed.

It is well known that the existing flora of Western Caucasia is of great interest from the point of view of the origin of the floras of Europe and Asia, as in it have survived to this day numerous types of plants which were widely spread over the Northern Hemisphere during Tertiary times. The Palæontological history of the Tertiary Flora of the Caucasus is very meagre. The Pliocene Flora of the Caucasus is discussed by me in my work on the presence of the leaves of the recent Caucasus beech-tree (Fagus orientalis Lipsky) and some other species of deciduous trees and shrubs in the Pliocene beds, the so-called “Aktschagyl Series”, of the Elisapethpol province. It is worthy of remark that the wood was found in seams interstratified with beds rich in well-preserved Pliocene shells, which could be determined with certainty. It was proved that in the southern Caucasus there existed in Pliocene times the same species of beech as at present.

The graptolite here described was discovered first in the St. Tudwal's peninsula by Mr. T. C. Nicholas in 1912 in the Llanengan Mudstones, but it was not then regarded as distinct from Azygog. lapworthi, though it seemed to possess certain features not recognizable in the Lake District specimens, the only area from which that species had been previously recorded. The discoveryof numerous other specimens by Dr. Matley in the Lleyn peninsula and by Dr. Greenly in the Bangor area has served to show that the characters wherein this species differed from Azygog. lapworthi are permanent and of specific value, and since, moreover, it occurs at a distinctly higher horizon than Azygog. lapworthi, being characteristic of about the middle of the zone of Didymog. extensus, a description of it seems advisable. In general it has been noted that it is in many respects intermediate in character between Azygog. lapworthi on the one hand and Azygog. suecicus on the other, and it is perhaps significant that it occurs upon an horizon between the two.

Last summer we spent seven days with Mr. E. B. Bailey investigating some of the evidence upon which he bases his interpretation of the structure of the South-West Highlands, and we feel that our experience should be at the disposal of others interested in the subject. Mr. Bailey's full account of his theory will shortly appear in the Quarterly Journal of the Geological Society of London, and an abstract has already been printed in the Proceedings of that Society, dated April, 1921.

Definition.—Shell large, elliptical, subquadrate; valves moderately convex; inferior margin very slightly curved, almost straight; posterior end well rounded above, truncated below and straight, meeting inferior margin at rather more than a rightangle; cardinal margin very slightly arched, nearly straight, but passing gradually into posterior margin; anterior end rounded. Beak large, rounded, prominent, subcentral, elevated above hingeline, incurved, not directed forwards. Umbonal ridge nanow, straight, running obliquely backwards to posterior lower angle of valve and causing a slight angulation of the surface. Shell ornamented with regular equidistant sharp concentric lamellose striæ about 30–40 in number, rather suddenly bent at an obtuse angle on crossing the umbonal ridge.

Plate XIV shows two photographs of a model I have recently made in order to show the outward aspect of Peloneustes philarchus, a pliosaur from the Oxford Clay. It is based on the complete mounted skeleton now in the British Museum (Natural History), Cromwell Road, a part of the well-known Leeds collection. This skeleton has a length of 10 ft. 6 in., and my model is 23 in. long, so the scale is roughly about 1:5. No other museum possesses a mounted skeleton of this genus, the nearest thing to which is the Trinacromerum, described as a Cretaceous plesiosaur by Dr. S. W. Williston in his work on Water Reptiles of the Past and Present, Chicago, 1915, where a restoration is shown on p. 89, fig. 42. The specimen is in the Museum of the University of Kansas. This same Leeds collection has given us two fine mounted skeletons of the genus Cryptoclidus, of the family Elasmosauridæ, and now we have also this fine mounted skeleton of Peloneustes, which belongs to the Pliosauridae. Hence it is now possible for geologists to see at a glance the chief characteristics of these two families, and my hope is that this model may be of some use to students of Palæontology. In making the model I have had the advantage of much valuable assistance from my friend, Mr. E. Godwin, an accomplished sculptor, without whose assistance I doubt if it could ever have been completed; for when I attempted to model the head I found a task that was beyond my power to accomplish properly, not having had any training in the art of sculpture.

Pembrokeshire is, on the whole—for Wales—a comparatively low-lying county, a somewhat dissected peneplain not usually rising much above four or five hundred feet above sealevel. Apart from the ragged stacks which rise up above the level of this peneplain in the northern part of the county—Carn Llidi and Pen-berry near St. Davids and the Stramble Head masses near Fishguard, for example—there is only one really prominent feature in the whole Pembrokeshire landscape, the Mynydd Prescelly, which rise near the western end of their ridge above Rosebush to a height of 1,760 feet.

1. The direction of the ridge is roughly parallel to the line of the moraine in Holderness as sketched by Carvill Lewis. 2. The material of the gravels is ice-collected, but is well waterworn though not rounded. The bulk of the pebbles are of northeastern England and Yorkshire origin, and a small proportion of Scandinavian rocks is present. 3. The stratification is horizontal and current bedding is frequent. 4. There is no seasonal banding nor any alternations of broad and narrow parts along the length of the ridge.