Geological Society of London. 333 



connection with these beds, is a misnomer ; there are beds which 

 are superficially like fine grits, but they are found to be Radiolarian 

 deposits. 



The Codden Hill Beds occur along a comparatively narrow belt 

 of country, a short distance within the northera and southern 

 boundaries between the Carboniferous and Devonian systems. 

 Starting with the northern exposures, the authors give a description 

 of the beds as developed in various localities from the neighbourhood 

 of Barnstaple (Codden Hill itself, situated 3 miles S.E, of Barnstaple, 

 being a convenient starting-point), past Dulverton, to Ashbrittle in 

 West Somerset. On the south the beds are traceable from Boscastle 

 to the neighbourhood of Tavistock, and on the east side of the 

 Dartmoor granite they are found near Chudleigh and Bovey Tracey. 



At present there are not sufficient data for estimating the thickness 

 of the Eadiolarian deposits ; but they are probably some hundreds of 

 feet thick, though the whole does not consist of beds of organic 

 origin. In a quarry in the Launceston district 50 feet of Eadiolarian 

 cherty rock are seen without admixture of shale. 



A detailed description of the lithological characters of the rocks 

 of the series is given, and analyses by Mr. J. Hort Player ; a marked 

 feature of their composition is the very general absence of carbonate 

 of lime. The microscopic characters of the rocks are also described, 

 and the small amount of detrital matter in the beds of the series is 

 noted. 



Forms belonging to 23 genei'a of Radiol aria have been recognized, 

 included in the orders Beloidea, Spliceroidea, Prunoidea, Discoidea, 

 and Cyrtoidea ; in addition a scanty but significant fauna of corals, 

 ti'ilobites, brachiopods, and cephalopods is present in some thin shaly 

 beds near Barnstaple. Nearly all the forms are diminutive. The 

 trilobites are described by Dr. H. Woodward, the brachiopods by 

 Mr. F. A. Bather, and the cephalopods by Mr. G. C. Crick. Of the 

 25 species of fossils other than Radiolaria which have been deter- 

 mined, several are only known elsewhere from the Lower Culm of 

 Gei'many, while others are common to the Carboniferous Limestone 

 of the British Isles and Belgium. 



These fossils tend to confirm the view that the Lower Culm 

 Measures are the deep-water ^equivalents of the Carboniferous 

 Limestone in other parts of the British Isles, and not shallow-water 

 representatives of deeper beds occurring to the north, as was formerly 

 supposed. In connection with this it is worthy of note that the 

 deep-sea character of the Lower Culm of Germany, which corresponds 

 with our Lower Culm Measures, was maintained by Dr. Holzapfel 

 even before the discovery of Radiolaria in the beds of Kieselschiefer 

 furnished such strong evidence in support of this view. 



2. "The Geology of Mount Ruwenzori and some Adjoinino* 

 Regions of Equatorial Africa." By G. F. Scott-Elliott, Esq., M.A° 

 B.Sc, F.L.S., and J. W. Gregory, D.Sc, F.G.S. 



Ruwenzori is a mountain between the Albert and Albert Edward 

 Nyanzas. Topographically it is a narrow ridge which extends for 

 about 50 miles in a direction from N.N.E. to S.S.W. Its summit 



