586 REPOET— 1880. 



into a lofty cordillera, tlie highest peak of which attains an elevation of nearly 

 4400 feet above the sea. In this series of elevations are many eruptive rocks. The 

 centre of the island is occupied by a fertile plain of rich soil on a base of Miocene 

 {moyen) in the area of which are lacustrine beds. There are cretaceous beds, some 

 abimdant fossiliferous deposits, and some magnificent conglomerates of rich gold, 

 red, and black coloiu's. Some of the limestones exhibit the richest colours of 

 marble. 



This slight general sketch is sufficient probably to interest the practical investi- 

 gator, and the Grotto de I'Homme Mort, with its abundant fossils, would alone well 

 repay an examination. 



There are some fine caves in Minorca, but the beautiful effects of the Cueva de 

 la Hermita in the larger island tend speedily to make them forgotten. 



The entrance to this cave is at a considerable elevation on the coast, which 

 Deing attained the descent is easy. The dimensions are imusual, and the inspection 

 occupies some hours. At intervals Bengal lights are burned, when a view opens 

 which puts even the elegant tracery of Gothic and Moorish architecture aside. 

 Long lines of light, straight, and uniform columns seem to multiply the effects of 

 AVestminster Abbey, while there is hardly a form, from magnificent organs, to 

 pxilpits, side chapels, and even mural monuments, that the eye does not figure to 

 itself as realities. The progress of the stalactitic formation has evidently been 

 arrested for centuries here, though still going on slightly in the caves in INllnorca. 

 With the exception of one or two small but good springs, there is no water on 

 either island. Rain is collected in the winter in tanks and drawn up from wells. 

 In some places, however, water is to be obtained by boring. 



The author then gave some analyses of lignite, and referred to the metalliferous 

 mines in Iviza and elsewhere. 



7. On a Striated Stone from the Trias of Portishead. 

 By Professor W. J. Sollas, M.A., F.B.S.E., F.O.S. 



This was a description of a striated fragment of carboniferous limestone from 

 the Triassic breccia of Portishead. The striation was, however, not due to glacial 

 action, but it is of the nature of ' slickenside.' The fragment was derived from the 

 neighbourhood of the great fault which traverses the carboniferous rocks of the 

 vicinity. It is interesting, since it shows that slickensided fragments, when occur- 

 liiig in a breccia, can be at once distinguished from true glaciated fragments, and 

 could never deceive any experienced geologist. At the same time it might serve as 

 a caution in receiving statements with regard to the finding of striated fragments 

 which had not been submitted to competent authorities. 



8. On the Action of a Lichen on Limestone. 

 By Professor W. J. Sollas, M.A., F.B.S.E., F.G.S. 



The author referred to the presence of minute hemispherical pits sprinkled over 

 the surface of many exposed limestone faces. These he showed were produced by the 

 apothecia of a lichen, Verrucaria rupest7-is, as noticed by Sowerby. They are inte- 

 restmg as showing that the action of lichens is not purely conservative, but to some 

 extent denuding, and also as proving that very similar cavities to those made by 

 Cliona, which have been attributed to mechanical action, may be made by a vege- 

 table which has no hard parts, and is almost as motionless as the stone on which 

 i 1 grows. Here all other agencies being eliminated, we have a case of excavation 

 by purely chemical action, 



9. On Sponge-spicules from the ChalJc of Trimm,ingham,, Norfolk. 

 By Professor W. J. Sollas, M.A., F.B.S.E., F.O.S. 



This was an account of some sponge-spicules from the chalk of Trimmingham, 

 Norfolk. They occur in association with flint nodules which have been incompletely 



