Geological Society of London. 185 



In discussinfr the age of the Barbados rocks, the author states 

 that there is now no doubt that the following is the sequence : — 



T> • J n 1 T-> i? ( Low-Level : Pleistocene. 

 Raised Coral Reefs... { High-Level: Pliocene. 



i Archceopneustes-abruptus- \ Miocene (and possibly partly 

 Oceanic Series | limestone. > Pliocene) and partly Oli- 



( Thalassic Marls. ) gocene. 



Scotland Beds Oligocene (probably Lower). 



The fauna of the Low-level Eeefs proves their late Pleistocene 

 age. Until more mollusca are collected from the High-level Reefs, 

 it will not be possible to decide whether the whole are Pleistocene, 

 or whether some must be included in the Pliocene ; it is probable 

 that the latter will have to be done. The Scotland Beds are 

 referred to the Oligocene. This narrows the limit for the time of 

 formation of the deep-sea oozes. Further light is thrown on this 

 question by examining the evidence for the period of submergence 

 of the Panama Isthmus, from consideration of the resemblances of 

 the marine faunas on either side, and the earliest migrations of 

 terrestrial animals across the Isthmus since its elevation. He 

 puts the period of final emergence of the peninsula in Miocene, 

 or late Oligocene times, and maintains that there is no evidence 

 of the connection of Atlantic and Pacific in this region since then. 



He gives reasons for supposing that a subsidence of the Caribbean 

 Sea was simultaneous with this emergence of the Isthmus, and that 

 this subsidence plunged part of the area now occupied by land into 

 abysmal depths in which were deposited the deep-sea oozes of 

 Barbados, Trinidad, and Cuba. In some part of the Miocene or 

 Pliocene re-elevation began, and shallower-water deposits (the 

 ArchaiOjpneustes-\imfi%tone) were laid down. Elevation continued, 

 resulting in the formation of coral-reefs and their final uplift to 

 difiierent levels above the sea. 



2. " Whitehaven Sandstone Series." By J. D. Kendall, Esq., E.G.S. 



The Whitehaven Sandstone, with its associated shales, is a purple- 

 gray deposit sometimes having a thickness of 500 or 600 feet. 

 The author gives details of many sections of the series, which also 

 contain thin coal-seams and occasionally Sp^VoJ•&^s-limestone. 



He combats the view that it is stained Middle Coal-measure 

 deposit, and gives his reasons for believing that it rests uncon- 

 formably upon the Middle Coal-measures, and also that it has not 

 received its colour by abstraction of colouring-matter from the 

 Permian beds, but that the colour actually belongs to the deposit. 

 He describes sections which show that the deposit has a wider distri- 

 bution over the Cumbrian district than is allowed by previous writers. 



3. "Notes on the Genus Murchisonia and its Allies, with a 

 Revision of the British Carboniferous Species, and Descriptions 

 of some New Forms." By Miss J. Donald. 



The generic characters of Murchisonia as now defined are given 

 in the paper, and the various divisions of the genus are examined, 

 including four which appear to be intermediate between Murchisonia 

 and Pleurotomaria. 



