1. The reply by the Rev. O. Fisher (Geological Magazine, June, 1913, p. 250) to Sir Thomas Holland's note leads me to ask permission to place the geodetic case before your geological readers. I ask geologists to give a hearing to a geodetic computer.

The great Karroo System of South Africa was divided by its discoverer, Andrew Geddes Bain, into four formations on lithological characters. They are—

The Stormberg Series.

The Beaufort Beds.

The Ecca Beds.

The Dwyka Series.

It has long been recognized that the Dwyka conglomerate, which forms a large part of the lowest series, is of glacial origin, and the common occurrence of smoothed and striated pavements below it all along its northern exposure seems to show that it is the product of a great continental ice-sheet.

The following account of the genus Syringothyris is the result of work undertaken at the suggestion of Professor T. F. Sibly, and is intended as a preliminary to a revision of the British species of that genus, which I hope to present at some future date.

The Green Ammonite Beds of the Lias (called also the Wear Cliff Beds in the latest Survey publication on Lyme Regis) include the clays with occasional limestones that lie between the Belemnite Stone below and the lowest of the Three Tiers above. The lowest Tier contains ammonites of the margaritatus group, and the Belemnite Stone caps the top beds of the Belemnite Marls that may be placed in the ibex-valdani zone. So the Green Ammonite Beds may be said to constitute the upper part of such of the Pliensbachian or Charmouthian as lies below the Domerian. Buekman has applied the term ‘Charmouthian’ to this lower portion, thus restricting the term to a part only of what it originally included. I have already advocated the propriety of applying the term Charmouthian strictly with its original connotation, and would call those zones of it that lie below the Domerian,—Bonarelli's ‘Charmoutiano inferiore’—which certainly need an inclusive name, Carixian. The fullest published accounts of the Green Ammonite Beds are those in the Survey Memoirs, and may be summarized as follows: They extend from Black Ven on the west to Seatown on the east; traces only appear on Black Ven; the complete series occurs on Stonebarrow, though there “only the lower portion is well-exposed”; their thickness is about 100 feet, though variable, and as much as 125 feet to the east of Golden Cap; they consist of marly clays with ‘ferruginous bands’ and nodular limestones.

In a very interesting article on the Geology of Bermuda, published in this Magazine for September and October, 1911 (pp. 385–95 and 433–42, Pls. XVIII–XXIII), the late Rev. R. Ashington Bullen states, on p. 390, that Admiral's Cave at Spanish Point is in the Walsingham Formation. This statement is evidently due to a slip in map-reading, Admiralty Cove being the boat harbour of Admiralty House near Spanish Point, whereas the Admiral's Cave, whencethe Pœcilozonites nelsoni in the British Museum were derived, is the “cave near the calabash-tree” mentioned on p. 439. This cave owes its name to the visit of Admiral Milne, and the base of his stalagmite is still in evidence, bearing his tool marks. It is one of the largest and most remarkable of the many caves between Bailey's Bay and Tuckerstown.

In the Peterborough, Advertiser for December 16, 1911, there appeared an illustrated article on a “recent discovery” of a silted-up pre-glacial river-valley, 250 yards wide, at Fletton, near Peterborough. Eliminating from that article a good deal of scientific romance, there remains a certain residuum of geological facts, so far as the determination of them by the writer of this note has been carried out, through the courtesy of Mr. A. Adams, the Manager of the London Brick Company's works.

For some time past I have had a difficulty in understanding how certain striated flints from various horizons stood, without breaking, the pressure to which they must have been subjected when such markings were imposed upon them. This difficulty increased when I found that thin flakes from the present land surface exhibited well-marked striæ, and as experiments with my presses had shown that even large flints will break up under no very great pressure, the possibility occurred to me of these scratches having altered since the flints were first subjected to the scratching process. I reasoned that if a point passed over a flint under pressure the area upon which the point impinged would be shattered, and that small plates or splinters of flint would be formed along the line of movement. I also concluded that, as with the thin plates which are produced on a flint when flaking, and which are not found upon implements which have been exposed to atmospheric conditions, these fragments would in time, by thermal effects, ‘weather out’ and leave a clean-cut groove behind.