88 Reports and Proceedings — Geological Sociefi/ of London. 



limestone 8 feet above the basalt. At Goblin Combe there is the 

 most characteristic and convincing section of ashy beds in the 

 district: the lenticular bands of coarse greenisli tuif, the limestone 

 intercalations, the close admixtnre of lapilli, limestone fragments, 

 and oolitic grains are stamped with the hall-mark of submarine 

 volcanic action ; lava closely underlies these breccias and tuffs. 

 'J'here is evidence of only one volcanic episode, which occurred in 

 all cases after the Zaphrentis-he(\s had been laid down, and before 

 the strata characterized by Chonetes and Streiitorlnjnchns were 

 deposited. (A table of certain broadly-marked horizons in the 

 Carboniferous Limestone, by Mr. A. Vanghan, F.G.S., is given for 

 reference.) The lavas are olivine-dolerites or basalts ; with pheno- 

 crysts of olivine or augite. They are frequently amygdaloidal, 

 sometimes variulitic; and in the variolites highly altered felspar- 

 phenocrysts occur. The rocks vary in grain, the coarsest being 

 those from Uphill and near Cadhury Camp, of the contemporaneous 

 character of which there is no direct evidence. The tuffs are all 

 highly calcareous, and most of them are best described as " ashy 

 limestones." The bulk of the lapilli varies from one-hundredth 

 part of the rock to about one-third, and their composition is closely 

 related to that of the basaltic lavas of the district. Quartz-grains 

 are abundant in the Goblin Combe rocks, and these rocks are 

 frequently oolitic. 



2. "The Rhsetic Beds of England." By A. Rendle Short, Esq., 

 M.B., B.Sc. (Communicated by Prof. S. H. Reynolds, M.A., F.G.S.) 



The paper opens with a description of four new exposures of these 

 rocks : one at Redland rests upon Carboniferous Limestone, and is 

 interesting because the ' Bone-bed ' is very ill-developed on receding 

 irom the old shore; a second is at Stoke Gifford, with a continuous, 

 Avell-developed landscape marble, the Insect Bed, and no bone-bed ; 

 a third at Cotharn Road (Bristol) yields baryta, celestine, and 

 Naiadita at special horizons containing no other fossils ; and the 

 lourth, at Aust, has given measurements of the uppermost 13 feet, 

 which are inaccessible from below. Next an account is given of the 

 constituent beds, with special reference to the conditions of deposition. 

 The Bone-bed is of wide distribution ; it frequently occurs in pockets 

 on a flat surface, or spread out over that surface ; it contains Irag- 

 inents of rolled marl, rounded pebbles of Carboniferous Limestone, 

 and pebbles of quartzite and well-rounded quartz. The author 

 concludes that it was formed during a stormy period, alter the sea 

 had made its first irruption into the dried-up or silted-up level 

 surface of the Keuper Lake. The Naiadita-heda appear to have 

 been formed in very shallow, and perhaps only slightly saline, water, 

 and the calcareous matter associated with them may have been mud 

 washed from the Carboniferous Limestone. Only after the White 

 Lias period did the water finally become moderately deep. The 

 area of deposit appears to have been a gigantic shallow lagoon 

 connected with the open sea to the south, and the fauna was derived 

 fiom the direction of Germany. A short account is given of some 

 of the Continental Rhsetic formations, followed by a list of Rhaetic 



