August 30, 1877] 



NATURE 



379 



thought that these pebbles were probably derived from the now 

 submerged granite. The age of the metamorphism is clearly 

 pre-triassic, for the triassic strata of the district contain pebbles 

 of metamorphosed rock. 



On the Drift 0/ Plymouth Hoe, by J. H. Collins.— The 

 author stated that excavations were nearly always going on in 

 the neighbourhood of Plymouth Hoe, and that fresh sections of 

 the so-called raised beaches and glacial deposits were continually 

 being exposed. 



He had lately visited the Hoe, Mt. Batten, and Deadman's 

 Bay, in company with Mr. Whitley of Truro, and had found 

 gravels, sands, and clays lying in the hollows of the limestone, 

 and filling fissures and caverns. The gravels were sometimes 

 cemented by stalagmite into a conglomerate. The pebbles were 

 composed of quartz, limestone, tourmaline schist, greenstone, 

 blue and red grit, hard clay-slate, schorl rock, granite, elvan, 

 flint, chert, stalagmite, and one pebble of granite ; all of which 

 the author considered had been derived from the rocks of the 

 neighbourhood within a few miles. None of the pebbles were 

 in the least degree ice-scratched, and there were very few 

 angular fragments of any kind. 



The gravels had yielded bones of rhinoceros, elephant, and 

 other animals of the so-called "Mammoth period." The 

 author discussed the evidence of local denudation, and adopted 

 or arrived at the following conclusions : — 



1. The deposits are not raised beaches. 



2. They are not glacial. 



3. They were formed rapidly, 



4. Gravels, fissure deposits, and cave deposits are of the 

 same age. 



5. That they belong to the Mammoth period. 



6. There is no evidence in the immediate neighbourhood to 

 carry back their formation more than a few thousand years. 



Notes on the Devonian Rochs near A^cwton Abbot and Torquay, 

 ■zi'ilh Iicmarks on the Subject of their Classifieation, by H. 13. 

 Woodward, F.G.S. — After having alluded to the imperfect state 

 of the information respecting the Devonian rocks, especially in 

 regard to local details of structure, the writer pointed out that 

 the succession of strata near Newton Abbott and Torquay was 

 (in descending order) as follows : — 3. Limestone ; 2. Slates ; 

 I. Red Sandstones. He noted the resemblances in lithological 

 characters between these beds and the lower carboniferous rocks 

 and old red sandstone, with which they were classed fifty years 

 ago by De la Beche. lie likewise drew attention to their rela- 

 tions with the Culm measures, observing that while there were 

 indications of conformability to them, no positive proof to the 

 contrary had been established ; and the supposed instances of 

 unconformability were all of them, as Jukes had considered, 

 capable of explanation by faults and other disturbances. Atten- 

 tion was drawn to some striking cases of such phenomena. The 

 impossibility of accepting fossil evidence alone was insisted 

 upon, inasmuch as its value in classification could only be 

 gained after the stratigraphical relations of the beds had been 

 made out, and at present the exact horizons from which many 

 of the species had been collected was not determined. 



Further, the theory that the Devonian rocks were the equiva- 

 lents in time to the old red sandstone required the existence at 

 this period of a great barrier between the marine deposits of 

 the former group and the freshwater accumulations of the latter, 

 and there was no physical evidence in support of this. Taking 

 all the facts into consideration, Mr. Woodward argued that they 

 were in I'avour of the classification proposed by Jukes, which 

 regarded the lowermost Devonian rocks as old red sandstone, 

 and the slates and limestones as lower carboniferous, formed in 

 an area which constituted a zoological province differing to some 

 extent from that in which these rocks were deposited further 

 north in the British area. 



On the Drjonian System in England and Belgium, by Prof. 

 G. Dewalque. — Having surveyed, last year, the Devonian system 

 of this country, I avail myself of the meeting of the British Asso- 

 ciation to ofler a few remarks on the results of my survey. As 

 my visit was short I cannot lay claim to a minute acquaintance 

 with this great formation in England ; but, as well acquainted 

 with it in Belgium and the Rhenish provmces, I hope the 

 following remarks may prove of some interest to the Associa- 

 tion : — 



I had not time to visit South Devon. As regards North 

 Devon my conclusions are as follows : — i. The metamorphic 

 character is more prevalent there than in Belgium, especially in 

 the middle and the upper divisions. 2. All this series is per- 

 fectly continuous, from Barnstaple to Lynton. Nowhere is there 



a reappearance of such identical rocks as to prove a fault, by 

 repetition of the series. 3. The sandstones of Baggy Point and 

 Marwood (Cueullaa zone) perfectly agree, both lithologically and 

 palKontologically, with certain portions of our " Psammites du 

 Condros." The red sandstones of Pickwell Down correspond 

 to the lower part of these Psammites. 4. The limestone of 

 Ilfracombe represents, as has been previously stated, on palseon- 

 tological evidence, the "stringocephalus limestone" (Calcaire 

 de diet) of Belgium and Germany ; but the lithological appear- 

 ance of the rock is very different. Hence it is easy to compare 

 this Devonian series with that of the Continent. In this respect 

 I differ but little from Mr. Etheridge. 5. The Devonian lime- 

 stone is much more abundant on the Continent than on this 

 side of the Channel. I think, moreover, that the same is to be 

 said of the carboniferous formation, that is to say, the mountain 

 limestone is replaced in North Devon (at least in part) by the 

 beds of Barnstaple and Pilton. In the slates of Pilton I found 

 beds and nodules of siliceous concretions, which represent, I 

 think, the (:/(tv/ of the carboniferous limestone, or the so-called 

 phthaniles of our "calcaire carboniiere." 



As to the old red sandstone I spent a week in Hereford, but 

 saw very little of it, I could only hammer conveniently the 

 " cornstones," of which I had from the descriptions a very im- 

 perfect notion. Such limestones occur identically in Belgium, 

 with red shales, sandstones, and conglomerates in the northern 

 trough, or " bassin de Naraur." This fact seems to me of the 

 highest value, for it leads me to this paradoxical conclusion : 

 the old red sandstone of the United Kingdom is a marine for- 

 mation, probably formed in the same ocean as the Devonian. 

 The old red of Belgium lies regularly between limestones with 

 Stringocephalus Burtini and others with Spirifer disjunctus. 

 That is certainly a marine formation, and the same must be the 

 case with the English old red sandstone. 



On the Succession of Jhe Falceozotc Deposits of South Devon, 

 by A. Champeinowne, M.A., F.G.S. — The Great Devon 

 limestones, the author concludes, are, as Mr. II. B. Wood- 

 ward has said, the highest rocks of South Devon, and the belief 

 in a series of slates and red sandstones overlying them, is a 

 fallacy. The beds which do succeed the limestones are the 

 Culm measures (upper carboniferous), and from the field-work 

 of Messrs. Woodward and Read there is reason to believe them 

 perfectly conformable. In this ca'e the difference between the 

 Devonian and carboniferous limestones would be one of life 

 distribution — a geographical, and not a chronological, difference. 

 This would probably have been long ago recognised had the 

 characteristic ichlhyolytes of the old red occurred in the Staddon 

 beds. 



Note on the Carboniferous Coast-line of N^orth Cornwall, by 

 S. R. Paltison, F.G.S. — The portion of coast described extends 

 from near Bude to Boscastle, and belongs to the formation first 

 identified by Prof. Sedgwick in connection with the diagnosis 

 made at Bideford by him and Sir R. Murchison as culm, or 

 lower coal measures. Bude lies in or on the centre of the 

 formation. The strata have a general northerly dip, and pro- 

 ceeding southwards down the coast of course lower beds 

 become exposed. The Bude beds contain thin films of culm, 

 with associated plant-remains in a very fragmentary condition. 

 Prof. Morris many years ago in a note published in the Pro- 

 ceedings of the Geological Society of Cornwall, identified some 

 of those remains as Cahunitcs, Sigillaria, and Aslerophyllites. 

 Prof. Hull states the number of species in the North Devon 

 beds, of which these are the continuation, at twenty-three, and 

 Mr. Townshend Hall at twenty-six. The Bude beds are continued 

 by foldings and succession downwards, but on arriving at St. 

 Gennys a system of deep-blue schistose sandstones appear and 

 form the base bne of the cliff along the remarkable coast landslip 

 which extends for two miles. From these dark-blue beds frag- 

 ments or nodules containing goniatitcs appear on the beach. 

 Then comatile-beds extend from Carne Beak to the cliffs 

 in the parish of St. Juliott. They are most abundant at 

 the St. Gennys end of the landslip. Here, at a sand-path 

 descending to the beach, on the beach, are huge fragments of 

 fallen rock containing very fine large impressions of plants, 

 especially sigillaria. Proceeding towards Boscastle, at the 

 gloomy gorge of Pentagion, the soft black shales, so charac- 

 teristic ol Boscastle, form the bulk of the cliffs, but below them 

 rises a slaty rock once quarried, and in this I found the usual 

 fragmentary plants of the Bude rocks. This, with the 

 associated soft black beds, is the farewell rock of the 

 carboniferous, for at the cliff, on the south side of Boscastle, 

 slates arise under the black shales, which at the summit contain 



