inclined northwards, but occasionally has a dip southward and westward. The Kimmeridge Clay (K), which is squeezed up in low ridges in two or three places at the base of the cliff, rises at the south end of it until it is lost under the Portland Sands on the face of the escarpment. Up the slope so formed the angular débris extends to a height of about 200 feet, at which level it gradually thins off, leaving a slight depression or hollow free from the débris, between it and the slope of the escarpment (see woodcut, fig. 8, and Section 5, Pl. I.). At first sight nothing can seem more unpromising for the discovery of fossils; but I found them in two places, viz. at s (fig. 6), and again higher up, at a depth of about 12 feet from the surface and 80 feet above the base of the débris, in a bed of sandy loam underlying a large boulder. At the latter they consisted of the following species: 1. Bithinia tentaculata, Müller: opercula. 2. Planorbis parvus, Say, P. glaber, Jeffreys. 3. Linnæa peregra, Müll., var. maritima. 4. Pupa marginata, Draparnaud. 6. Cypris Browniana. In the former, s, they occurred in a small intercalated bed of brown loam near the base of the cliff and 50 feet deep in the débris. Here they were very rare, and of only one species, Pupa marginata-together with one undeterminable leaf-impression? This angular débris stretches only a short distance inland in the direction of the Verne, and is quite disconnected with the talus (T, fig. 8) formed by the existing cliffs or escarpment. I believe, Fig. 7.-Section at Sugton Pit near Southwell. however, that the broken and disturbed state of the upper 2 to 3 feet of the fissile Purbecks in all the higher parts of the island is part of the same phenomenon. In the small valley passing down by Southwell this is overlain by another bed, due rather to rain-wash (see fig. 7, p. 39). At Lulworth and Arish Bay, a local angular drift-deposit of the some age flanks either side of the valley facing the sea. Other Drift Beds. The wide undulating tract of the Kimmeridge and Oxford Clays, Coral Rag, and Forest Marble between Portland and the Chalk range is generally perfectly bare. It is only at the following places that I have met with other small beds of drift : 1. At levels of from 30 to 50 feet on the skirts of the hill between Portland Ferry and Wyke. It is a coarse gravel, composed of subangular Chalk-flints and Greensand chert* with a few pebbles of Portland flint, from 2 to 4 feet thick, and reposing upon a worn and eroded surface of Kimmeridge Clay and Coral Rag (b", see Map and Sect. Pl. I.). 2. Between Melcombe Regis and Furzeland are two low flat hills about 50 and 60 feet high, capped by a peculiar drift-gravel, which is worked on the left of the road turning off to East Chickerel. It consists almost entirely of subangular fragments of chert from the Upper Greensand, imbedded in a red clayey matrix, from 2 to 8 feet thick, sometimes covered with 2 feet of grey clay, and reposing in patches upon a very irregular bed of Oxford Clay. It was only after some search that I found in it a few small subangular chalk flints and a small pebble of white quartz. A similar gravel caps the hill half a mile west of the bridge over the Back-water (c, Pl. I.). 3. Traces of a coarse gravel-drift, chiefly of chert, exist on the top of Crook Hill, near West Chickerel; but there is no bed of it. 4. On a hill between Weymouth and Broadway, east of Radipole, and at a height of about 70 feet, is a thin bed of gravel, composed of subangular chalk- and Portland flints, Greensand chert, large Sarsen-stones, and Tertiary flint-pebbles (c). 5. A similar gravel caps one of the hills midway between West Chickerel and Portisham. 6. A remnant of a much thicker deposit of gravel exists on the cliff immediately east of Osmington Mill, and again east of Radcliff Point, at the higher level of about 150 feet. It consists almost entirely of a mass of brown subangular chalk-flints, many of them of large size, with a few fragments of Greensand chert, sandstone, and Portland flint, in red clay and sand, 8 feet thick (b'). 7. On a still higher level of about 300 feet, and capping the hill on the right hand of the road between Preston and Osmington, a small patch of fine flint and loess drift lies in hollows on the Portland Stone (b). 8. Another thick bed of still older gravel, composed chiefly of local Tertiary materials, overlies, and is scarcely separable from, the Tertiary beds at places on the highest points of the Chalk range †. *On one fragment was a cast of Pecten quadricostatus. As I am uncertain of the extent of this bed, I have marked it on the map in one shade with the Tertiary beds, which also consist chiefly of sands and shingle-beds. It is from 10 to 15 feet thick, and of a red and ochreous colour, but it weathers white. The matrix is a sandy loam and clay. Nine tenths of the gravel consist of well-rolled chalk flints; and the other tenth consists, in the order of their relative abundance, of:-1, large and small white quartz and red quartz pebbles; 2, subangular fragments of Portland flint; 3, chert and ragstone of the Greensand (some of the latter in blocks of considerable size; one was 5 × 2 × 1 feet); 4, small subangular fragments of red porphyry; 5, jasper; and 6, a few small fragments of worn shelly limestone (Forest Marble ?). In places the gravel is much disturbed. The pit from which the above collection was obtained, is within 50 or 60 feet of the summit of Blackdown (790 feet). The gravel is probably of older date even than the mammaliferous drift of Portland, and may belong to some part of the Glacial period. In none of these beds of gravel could I find either bones or shells; but the remains of the elephant (Elephas primigenius?) have been found in a low-level drift (a, in Map, Pl. I.) at Radipole, probably that which follows the course of the small stream, and was noticed by Dr. Buckland as being of some extent in the valley near Upway; but no section of it was exposed at the time of my visit. A lowlevel valley-gravel also occupies the small Abbotsbury valley; and a trail of gravel extends over the hill north of it and on the lower slopes of the Upway valley. Capping the high chalk ranges of Upton, the White Nore, and Abbotsbury, is a thick bed of perfectly angular sharp chalk-flints in a reddish clay reposing on a deeply indented surface of chalk, while a similar angular drift composed of fragments and masses of chert and ragstone cap the Upper-Greensand hills north of Abbotsbury. It is not, however, my intention to describe this or No. 8 further at present; I merely refer to them as having been the storehouses whence much of the later drift-beds have been supplied. Calcareous Tufa Deposit. The raised beach on the east cliff is often cemented by carbonate of lime into a compact conglomerate. It also forms in places detached porous masses of tufa of considerable size, and fills up the interstices of the Purbeck débris. It is newer than the angular débris; for in a section on the cliff near the lower lighthouse the following is the order of superposition :— Tufa full of recent land-shells Broken surface of Purbeck, with traces of beach. 1 foot. This tufa is apparently due to some springs which still occasionally issue on the slope of the hill a short distance inland from the beach, and which formerly gave off a greater volume of water than at present. Concluding Remarks. The study of the chronological relation of these deposits is a subject of much interest. As before mentioned, Portland, with its capping of the fissile beds of the lower Purbecks, presents a bare rock-surface. There is no trace of any more recent Secondary or of any Tertiary strata anywhere in the island; nevertheless the mammaliferous drift of the Admiralty Quarries contains well-worn pebbles of chert from the Upper Greensand, and of iron sandstone and Sarsen-stone, together with small blocks of the latter from the Tertiary strata, and chalk-flints from the hills between Upway and Dorchester, a distance of from eight to ten miles to the north of Portland, from which it is separated by a low plain of older strata, where none of the few scattered drift-beds has any resemblance to the Portland drift. This latter stands alone; and although at a greater distance from the Tertiary strata in situ, it contains nevertheless a much larger proportion of their débris than do any of the nearer and lower-level drift-beds. These Tertiary and Greensand materials could only have been transported to their present position by a floating iceberg or by a running stream. The former is not probable, as the transported rock-specimens are all waterworn and mostly well rounded, and they are associated with mammalian remains and a silt which has the ordinary characters of a freshwater loess, although, as is common with the loess itself, no shells have been found in it. I can only conclude, therefore, that this deposit has been formed by direct transport by a stream running southward from the Greensand and Tertiary area and passing over Portland; and this, necessarily, could only have taken place when the intervening district was bridged over by strata since removed. It follows that the denudation of the plain of Weymouth and the deposition of the several drift-beds found thereon are of more recent date than the mammiliferous drift of Portland (see Sections 1 and 2, Pl. I.). If the dip of the Portland and Purbeck beds at Portland be prolonged northward, they would reach an elevation of about 1000 feet at Broadway, and of about 1500 feet at the Ridgeway, and thus interpose a high ridge between Portland and the newer strata from which the pebbles of the Portland drift have been derived; consequently either the crest of the anticlinal had then been removed, and a high level plain of the Jurassic strata extended from Portland to the Greensand and Tertiary area, or else at that time the north end of Portland had not been upheaved, and a continuous plain of Portland and Purbeck extended to the Bill of Portland from the point where those formations were brought into contact with the newer strata by the great Ridgeway fault. Looking to the facts that the Portland drift is at a height of 400 feet, or nearly that of the supplying Greensand and Tertiary strata-that the Portland plateau is prolonged northward to 100 feet higher, and is then abruptly truncated-and that the drift-bed, although rich in Tertiary sandstone, does not contain a fragment of the Coral Rag, Forest Marble, or other rocks which, under the first-named conditions, must have formed the surface of the plain over which the stream would have passed, it is, I think, more probable that the second condition, or that of a gradually sloping plain of Portland and Purbecks extending from the Bill of Portland to the Greensand and Tertiary area, obtained at the period of the Portland Drift (see Section 3, Pl. I.). The disturbance which raised the Weymouth district and elevated the north of Portland, is the central anticlinal of the Jurassic series (A in Map, Pl. I.), which runs east and west and brings up the Forest Marble between Broadway and Buckland Ripers; for I find that on prolonging the angle of rise of the Portland beds northward, and that of the Purbeck beds (where they crop out on the south of the great Ridgeway fault) southward, the two planes meet exactly over the ridge of that line. The great Ridgeway fault is, I believe, of older date. If I am right in this intepretation, then it is probable that the anticlinal bringing up the strata below the Chalk at Purbeck, and likewise the great upheaval at the back of the Isle of Wight, both of which are on the same line of disturbance as the Broadway anticlinal, are also of the same age; and we thus obtain a marked instance of elevation and denudation during the Quaternary period. The great difference of level between the mammaliferous drift and the raised beach might lead to the supposition that they were of different ages. Still, as the former is not a case of capping horizontally an isolated hill, but of forming part of a sloping surface continuous from the northern to the southern end of Portland-and as that surface, for the reasons before mentioned, had its inclination given it subsequently to the deposition of the drift, and when consequently its level above the sea may not have exceeded from 100 to 150 feet, or about 50 or 100 feet above that of the old beach, while the old beach itself (like the drift-bed) contains materials derived from the same Tertiary and Greensand area, it is probable that the drift-bed and the raised beach were contemporaneous. In fact, while in the upper part of the Admiralty Quarries the drift-bed attains a height of 400 feet, at the angle of the road near the new church it is only 346 feet high, still dipping in the direction of the Bill. On the other hand, the Old Beach, which at the Bill is only 24 feet above the present beach, rises gradually northward until near the Sandholes, where it attains a height of 36 feet. It is probable, therefore, that the old stream emptied itself a short distance off the present Southwell shore into a small bay, of which the land passing from the Sand-holes in the direction of the lower lighthouse formed the western horn. The Portland raised beach is by far the most interesting one in the south of England, whether for its extent, its thickness, its large exposure, or its general conditions. In the first place, the materials of which it is formed are partly of local, but still more are of distant origin. Although it contains pebbles of Portland Stone and chert, it is essentially a chalk-flint shingle with a considerable proportion of pebbles of chert from the Greensand. It also contains subangular brown-coated flints, derived apparently from an old gravel, with a few which may be referred to Tertiary strata, together with some angular fragments of chalk-flint showing no wear. With these are a number of pebbles of red sandstone and of light-coloured and |