134 Beports and Proceedings — Geologists' Association. 



Tn point of execution and finish the marginal sections are de- 

 ciledly inferior to tlie main body of the map. They are six in 

 number, and illustrate the geological structure of the Highlands, 

 Forfar, the Southern Uplands, the Midland Valley, and the Volcanic 

 Eegion of Mull and Morven. 



The igneous rocks have been laid down with special care. They 

 ara distinguished by a separate type of colour according as they 

 belong either to the acidic or pyroxenic and basic series ; the main 

 species of each group being separated by variations in depth of 

 tint. Much advance has also been made in their chronological 

 arrangement. The main geographical masses, whose age has been 

 satisfactorily determined, are marked upon the map by the letter or 

 figure significant of the epoch to which they belong. The outlines 

 of the chief granitic areas of the Uplands and Highlands are 

 corrected ; but although the author has elsewhere shown that there is 

 a high probability that they are of Old Red age, he has wisely 

 refrained from fixing their systematic position upon the map. The 

 ring of igneous rock which surrounds the great Valley of Central 

 Scotland is now lettered as being composed of two portions of very 

 different ages. The Pentlands and Ochils belong to the Old Eed 

 Sandstone, while the Campsie Eells and the hills of Eenfrew and 

 Cunningham are classed with the Lower Carboniferous. The Cheviot 

 porphyries are correctly mapped for the first time, and are definitely 

 assigned to the earlier of these epochs. The main sheets of igneous 

 rock among the Upper Old Eed beds of Eoxburgh are inserted, 

 and the peculiar amygdaloidal trap which lies at the base of the 

 Carboniferous Sandstones of Eiccarton, is traced continuously from 

 the northern flanks of the Cheviots into the well-known igneous 

 mass of Barnswark in Annandale. 



Of the thorough correctness of the geological portion of the map 

 we can speak with perfect confidence, as it has been our faithful 

 companion in many a geological excursion, not only, in the well- 

 known beds of the Central valley, but also among the more enigma- 

 tical strata of the Uplands and Highlands, and we have invariably 

 found it correct. 



In the multiplicity of its detail, in the conscientious accuracy of 

 its workmanship, and in its fitness for the special purpose it is in- 

 tended to subserve, this map is unique in its class. It is creditable 

 alike to its author and to its publisher, and is simply invaluable to 

 those who wish to possess an accurate knowledge of the geological 

 structure of Scotland. C. Lapwoeth. 



lazBi^oiiTS jL.isriD i^ieooiBiEZDiisrG-s. 



The Geologists' Association. — At a meeting held at University 

 College on the 4th January last, Mr. H. Goss, F.L.S., F.G.S., etc., 

 communicated a paper on "The Insect Fauna of the Secondary or 

 Mesozoic Period, and the British and Foreign Strata in which 

 Insect-remains have been detected." After making some intro- 

 ductory observations and calling attention to the writings and in- 



