EXPLANATION OF PLATES LIV-LVII. [All figures are of the natural size, except where otherwise stated.] Fig. 1. Lucina globulosa, Deshayes. Right valve. (P. 625.) 2. Busycon canaliculatum (Linné). (P. 631.) 3. Dolium sp. (P. 639.) 4. Distorsio cancellinus (Roissy). (Pp. 629-30.) 5. Voluta D'Archiaci, sp. nov. (P. 640.) 6. Cantharus Martinianus (Nætling). Back view, x 2. (Pp. 630-31.) 7. Do. do. Front view, x 2. PLATE LVI. Fig. 1. Batissa kodoungensis, Noetling. Right valve. (P. 624.) 2. Do. do. Do. do. dentition. 3. Natica (Ampullina) grossa, var. oblonga, Deshayes. Back view. Fig. 1. Cassidea acanthina, sp. nov. (P. 629.) 4. Voluta pernodosa, sp. nov. (P. 640.) Back view. (Pp. 627-28.) 5. Cypræa Everwijni (?) Martin. Front view. (P. 628.) Apical view. 7. Cypræa (Cyprædia) elegans, Defrance. Back view. (P. 629.) do. Front view. 8. Do. DISCUSSION. The CHAIRMAN (Dr. J. J. H. TEALL) asked for the evidence on which the Pliocene rocks had been estimated at 20,000 feet. Mr. R. BULLEN NEWTON Congratulated the Author on the interest of his paper. He thought, however, that some additional information, in connexion with the Author's tabulated horizons, might be acceptable. The Irawadi Series, with its terrestrial and fluviatile vertebrate fauna, described by Buckland and Clift in 1828, from material collected by John Crawfurd, had recognized affinities with that found in the Siwalik-Hill formation of India, as well as with that yielded by the Pikermi deposits of Greece. All these beds were frequently alluded to as of Pliocene age, whereas in reality they were of Upper Miocene age, and belonged to the Pontian stage of those rocks (see A. de Lapparent's Traité de Géologie' 5th ed. 1906, pp. 1630 & 1632). The fact that the Author had been able to determine a European Miocene shell, Lucina globulosa, in the lower or marine part of the Pegu Group, was evidence in favour of recognizing those beds as belonging to the Helvetian-Tortonian portion of the Miocene System, since the above-mentioned shell was characteristic of that horizon. The Bassein Group, according to Dr. Nætling, contained, among other mollusca, Velates Schmideliana, one of the most typical shells of the Lutetian or Middle Eocene Period, which was found in Europe, Egypt, India, etc., and never occurred at a later stage of the Eocene, although Dr. Noetling regarded it as favouring the Upper or Bartonian division of that system. In India this gastropod occurred in the Khirthar Group of Sind. The AUTHOR thanked the Fellows present for the way in which they had received his paper, and stated, in regard to the thickness of the Irawadi Series, that he had only quoted Dr. Nætling's figures, which seemed to him to be very excessive. In conclusion, he expressed the hope that his paper would prove effective in re-introducing the subject to British geologists, and in stimulating interest in its problems. GENERAL INDEX ΤΟ THE QUARTERLY JOURNAL AND PROCEEDINGS OF THE GEOLOGICAL SOCIETY. Aber-chwil Fault (Glyn Ceiriog), Aci Castello (Sicily), pillow-lavas of, Actinacis Natlingi, sp. nov., 622 & Actinoconchus (?), 470 & pl. 1. Actinolite talc-rock' fr. New Zealand, Actinolitic rocks of Glendalough, 482- 83 fig., 487 et seqq. & figs. ADDISON, P. L., obituary of, lxix. fig. & chem. anals., 140 fig., 141– Alectryonia Newtoni, sp. nov., 635-36, Allanite in Glendalough rocks, 483, 487. ALLEN, H. A., [motion seconded by] ALLENDALE, LORD, obituary of, lxvi- ALLORGE, M. M., [on Cornish & Breton Alsop-en-le-Dale & Tissington Ry. Altarnun, see Buttern Hill. Alternating strain-slip defined, 308. Alton district (Hants), former & pre- America (North), chronology of Angles of rest of certain solids in Antigorite-serpentines, &c., 152-70 & map. 'Anvil-stone' (paleolithic) fr. Rus- Apatite in St. David's-Head 'rock- Aplite (soda-) of St. David's Head, superimposed characters of rocks, 600. manensis, sp. nov., 634-35 & metabistrigata, 623. Ashgillian Series compared w. Dolhir Assets, statement of, xlii. Athyris cf. planosulcata, 469-70 & Auditors elected, v. 'Augen '-like cracks, see Phacoidal. Augite-andesite (Pebidian), 366. Australia, South. See South Australia. Avening Green (Gloucest.), Llandovery BARON, Rev. R., obituary of, lxiv. Bartestree (Herefordshire), basic in- Basalts of Bartestree, 507-509 & pl. lii Basalt-dykes, Tertiary, in Colonsay, BASEDOW, H. (& G. D. Iliffe), on a Basic intrusive rocks of St. David's area, 379-81; of Bartestree, 501-11 Batissa kodoungensis, 624 & pl. lvi. showg. viscid flow-structure], v. Beaumontia aff. Egertoni, 70. BELL, J. M., 158, 165. BERTRAND, MARCEL, obituary of, l-liv. Biotite in Glendalough rocks, 488, |