Geological Society of London. 187 



unfossiliferons Cambrians of Wales, etc. The volcanic series has 

 already formed part of the subject of an Address from the Chair, 

 Oddly enough, the best defined pre-Cambrian, or fundamental 

 sedimentary series, is to be found in the North-west Highlands, a 

 district which only a few years ago was an enigma, but which we 

 hope may now supply a clue to regions more obscure. This, of 

 course, is the Toi-ridon Sandstone, which has a well-defined base and 

 a well-defined summit. Then there are certain rocks which some 

 regard as Cambrian, others as pre-Cambrian, such as the Howth 

 Hill and Bray Head beds, claimed as Upper Monian. Crossing St. 

 George's Channel, we find ourselves in Anglesey, a land of pre- 

 Cambrian mysteries. The older rocks have been described as 

 belonging to the Monian system, an arrangement much controverted, 

 and this controversy has extended to Shropshire, Lastly, there is 

 the long-standing contention as to whether the unfossiliferons 

 Cambrians of North Wales really belong to that system or should 

 be placed on a lower horizon. The Malvernian controversy relates, 

 in the main, to the crystalline schists. 



Under the heading of General Petrology is grouped a very large 

 series of papers, more than sixty in number, divided roughly into two 

 primary classes, according as they relate to the British Isles or to 

 foreign countries, the former class being alone considered in detail. 

 The arrangement is topographical, and the rocks under this heading 

 may be of any age from the Archsean upwards. Scotland has yielded 

 seven papers in this group — most of them of very great interest and 

 importance, one or two being somewhat controversial. The subject 

 of contact-metamorphism is raised with reference to more than 

 one Scotch locality ; and from the Lake District there has been a 

 communication on the Shap Granite and associated igneous and 

 metamorphic rocks, which again brings this question into promi- 

 nence. Some of the papers relating to Wales have already been 

 dealt with in a previous Address, but the subjects of the Yai'iolite 

 and also of the Nodular Felstones of the Lleyn are noticed on the 

 present occasion. In Devonshire the rocks formerly known as 

 '• felspathio traps" have been described as basalts and andesites; 

 whilst the igneous origin of the Dartmoor Granite has been main- 

 tained against one of those theories which from time to time crop up 

 with respect to this well-known massif. Allusion is also made to 

 the controversy with respect to the Start rocks. There have been 

 four papers dealing with the Lizard peninsula, in which questions 

 as to priority of the several igneous masses and as to the origin of 

 the banded gneisses are entertained. It cannot be doubted that 

 considerable progress has been made of late towards a recognition of 

 the true character of these rocks, which, for the extent of territory 

 they occupy, are perhaps without equal in point of interest throughout 

 the British Isles. The Address concludes with a notice of the rocks 

 of Brittany and the Channel Isles, which have attracted the attention 

 of more than one author. 



The Ballot for the Council and Officers was taken, and the following were duly 

 elected for the ensuing year: — Council: H. Eauerman, Esq.; W, T. Blanford, 



