Geological Society of London. 233 



Geological Society of London.— I. — March 12, 1873.— Joseph Prestwich, Esq., 

 F.E.S., Vice-President, in the Chair. — The following communications were read: — 

 1. "Note on some Brachiopoda collected by Mr. Judd from the Jurassic Deposits of 

 the East Coast of Scotland." By Thomas Davidson, Esq., F.R.S., F.G.S. 



In this note the author stated that four species of Brachiopoda collected by Mr. 

 Judd were especially worthy of notice, two of them being quite new, and two new to 

 Britain. Three of them were obtained from the equivalent of the Kimmeridge Clay, 

 which was the more remarkable as the Brachiopoda of that formation are compara- 

 tively few. The new species described were Rhijnchonella SutherlamU and Terebratula 

 Joassi, derived, with Terebratula humeraUs, Rom., from the Upper Oolite of Garty 

 in Sutherland ; the fourth species is Terebratula bisiiffarcinata, Schlot., from the 

 Lower Calcareous Grit of Braamberry Hill. This note is intended to form an 

 appendix to Mr. Judd's paper on the Secondary Rocks of the east coast of Scotland, 

 and is accompanied by a plate. 



2. " On Solfataras and Deposits of Sulphur at Kalamaki, near the Isthmus of 

 Corinth." By Prof. D. T. Ansted, M.A., F.R.S. , F.G.S. 



After noting the traces of volcanic action east of the Pindus chain, the author 

 described the Solfataras and sulphur-deposits of the neighbourhood of Kalamaki as 

 furnishing indications that there is even now a real though subdued volcanic energy 

 in this part of Em-ope. At this place, about three miles east of the Isthmus of 

 Corinth, there is a series of cream-coloured and grey gypseous marls, broken by 

 narrow gorges and fissures. These marls, the stratification of which is much dis- 

 turbed, are loaded with sulphur. In the principal gorge there are several lateral 

 fissures, forming caverns, communicating with the interior by deep cracks ; these 

 caverns are completely lined with crystals of sulphur and other volcanic minerals,_ and 

 are rendered inaccessible by the large body of hot stifling vapours constantly_ emitted 

 through them. The temperature of this vapour, where it can be reached, is about 

 100° F., hut the floor of the caverns is too hot to stand on even near the entrance. 

 The author is of opinion that the rocks in this gorge might be profitably worked for 

 sulphiu-. Similar phenomena occur in several other places within about a mile of the 

 ravine described ; and the author was informed that this was the case also several 

 miles ftirther to the east. 



The author adverted to other signs of volcanic action to the west of these Solfa- 

 taras, and especially to the structure of the Acropolis of ancient Corinth, and inferred 

 that lines of volcanic action parallel to the spurs of the Alps of which Etna and Vesu- 

 vius and Santorin are the modern vents, ranged far to the north at no distant period. 



Discussion. — Admiral Spratt mentioned a cape in the Gulf of ^gina, which within 

 the historical period has risen to a considerable extent, some hundi-eds of feet, and 

 thus illustrates the influence of modern volcanic action. 



Mr. "W. W. Smyth wished that the author had drawn a more distinct line between 

 the Tertiary beds containing sulphur and those of still more recent origin. The beds 

 near Corinth reminded him much of some in Transylvania, and he was anxious to 

 know whether the direction of the fissures or other phenomena indicated any great 

 disturbance of the sti'ata. 



Prof. Ansted, in reply, mentioned that the fissures ran approximately north and 

 south, and were as nearly as possible parallel. He considered that they were con- 

 nected with the disturbances which have taken place in comparatively recent times 

 along the eastern coast of the Morea. The sulphur, which usually occurs in small 

 globular masses in gypseous beds, was found in these Solfataras in a crystalline form, 

 and in connexion with the fissures from which the heated gas issues. There was 

 therefore a marked difference in the manner of its occurrence both in Italy and 

 Greece. In Greece the sulphur deposit in nodules was found on the west of the 

 principal chain of mountains, and the crystalline sulphur on the east. In Italy the 

 crystalline sulphur is limited to the vicinity of Vesuvius, and the nodules are abundant 

 both in Sicily and on the east coast of the main land. 



3. " On the Origin of Clay-ironstone." By J. Lucas, Esq., F.G.S. 

 The author commenced by giving a general view of the varieties, chemical compo- 

 sition, and mode of occurrence of Clay-ironstone, and suggested that the formation 

 of all the bedded varieties may be explained by the supposition that they originated 

 in peaty or non-peaty lagoons or the alluvial flats of the deltas of the Carboniferous 

 formations, which would present semiterrestrial conditions, that is to s:iy a surface 

 exposed to the air, but subject to be covered by floods. Carbonic acid formed in the 



