288 Geological Society. 



loachitica. The calcareous nodules, which are not ferruginous, 

 occur in thin shale-beds, 2 to 3 feet thick; they commonly contain 

 a marine fauna, with goniatites, lamellibranchs, and fish-remains. 

 The fossil flora and the horizon of the beds are next discussed, lists 

 of plants being given from various localities ; and the conclusion 

 is reached that the rocks belong to the Middle Coal-Measures, and 

 that there is no evidence of Upper Coal-Measures. Conglomerates 

 of waterworn pebbles are also present, the pebbles being derived 

 plant -petrifactions, possibly of earlier age than the sandstones and 

 shales in which they occur. Two distinct and unmingled faunas 

 are present in the rocks : one consists of freshwater lamellibranchs, 

 and the other of marine fishes, cephalopods, and lamellibranchs ; 

 and the evidence as to horizon obtained from them agrees with 

 that yielded by the plant-remains. The paper concludes with a 

 bibliography. 



2. l The Titaniferous Basalts of the Western Mediterranean.' By 

 Dr. Henry S. Washington, For.Corr.Geol.Soc. 



In 1905 the author visited the volcanic districts of Catalonia, 

 (Sardinia, Pantelleria, and Linosa. He recognizes the existence in 

 this region of a hitherto unrecognized petrographic province, in 

 which the basalts contain a remarkably -high percentage of titanium. 

 The rocks are of Tertiary age. Labradorite, augite, and olivine are 

 the essential minerals, with titaniferous magnetite and apatite, and 

 in some cases subordinate nepheline. The rocks vary from compact 

 to highly vesi -ular ; they are not conspicuously porphyritic, though 

 small phenocrysts of augite and olivine, and occasionally felspar, are 

 sometimes present. Olivine-nodules occur in some cases. The 

 textures are those common in basalts, and ophitic relations are almost 

 wanting. A series of analyses is given : the silica varies from 44 

 to 52 per cent., the alumina from 12 to 19, and the titanium-oxide 

 from 2 to 5. The last oxide appears to be chiefly contained in 

 titaniferous magnetite. Phosphoric peutoxide is distinctly abundant 

 and appears to vary, as the titanium does, with the amount of iron- 

 oxides. Soda is dominant over potash in every instance. The 

 augites are almost, if not quite, colourless. The classification of ihe 

 rocks according to the quantitative system is discussed, and the 

 majority of the basalts fall into the 'Salfemane' class, the exceptions 

 being some of the Sardinian basalts and that of Graham's Island. 



The extent of the region is as yet problematical, and the author 

 points out that along the southern coast of France there are several 

 ' basaltic ' volcanoes, and it is possible that these may eventually 

 turn out to be connecting-links between the rocks of Sardinia and 

 those of Catalonia, or possibly extrusion southward is indicated by 

 the occurrence of phonolite at Maid Gharian near Tripoli. 



The Impulsive Motion of Electrified Systems. 



By G-. E. C. Searle. 



Correction : — 



On page 121 of the Philosophical Magazine for January 1901 



for " Since e is at right angles to the plane of r and U " 



read " Since ie s in the plane of r a::d u " 



