Sept. 9, 1875] 



NATURE 



407 



south, and the greater denudation of the pre-Deronian land of the 

 north. The Termian he wished to abohsh as a separate forma- 

 tion, as it was a group made up of some stained carboniferous 

 rocks and some of Sedgwick's previously described Magnesian 

 Limestone and New Red. He thought that the continental area 

 on whose submerged surfiice the New Red was deposited sunk un- 

 equally, and that conglomerates, where there was material to 

 furnish them, were formed along the receding shore line, but at 

 different dates as difiercnt parts of the land got down below the 

 waves. He challenged anyone to show a section in which a 

 greater break could be seen between the Trias and so-called 

 I'ermian than several which occur amongst various members of 

 the Upper New Red itself— and commented upon the unsatis- 

 factory character of the palKontological evidence and of the 

 strat graphical evidence derived from tracing lines through a 

 distiict where the rock was seldom seen. 



Prof. Hull commented upon the difficulty of introducing any 

 material changes in a nomenclature now so widely accepted. 

 Prof. Harkness stated that he was in favour of adopting the 

 classification of Silurian rocks given in Lyell's *' Student's 

 Manual." In reply, Prof. Hughes maintained his original 

 claims with much humour and energy. 



Prof. Hcbert's very interesting communication on Undulations 

 in the chalk of the North of i:"'rance had special reference to 

 the strata likely to be encountered in the drift-way of the 

 Channel Tunnel. The Professor considered that observations of 

 dips established the existence of two series of folds, one trans- 

 verse to the other, which by their intersection produce bosses, or 

 geological hills. The lower rocks, and notably the Grecnsand, 

 may thus come to the surface in the Channel, and admit the sea- 

 water through their porous substance. Sir John Hawkshaw was 

 present, and combated the geological difficulties with great suc- 

 cess. A course of no fewer than five hundred borings, made by 

 a plunger from the side of a vessel, had satisfied him of the 

 substantial accuracy of the geological map of the Straits con- 

 structed from shore observations, and the information yielded by 

 these bormgs was in his opinion adequate to prove that the 

 tunnel will run through Lower Chalk in its whole extent. A 

 small irregularity, bringing in some less compact rock, may be 

 successfully and easily encountered by the engineer. In answer 

 to a suggestion that the shallow holes made by the plunger 

 might be deceptive, owing to a superficial detritus along the 

 floor of the Straits, Sir John Hawkshaw explained that the 

 strong wash of the Channel produced a perfectly clean floor. 

 All along the Straits the instrument had brought up chalk where 

 chalk was expected, and gault where gavdt was expected, and 

 these formations had a perlectiy definite boundary upon the floor 

 of the sea. 



A paper by Mr. Sanders described some large bones from the 

 Rhaetic beds of Aust Cliff. The dimensions of these fragments 

 are so great as to suggest a large Dinosaurian, but the absence of 

 any medullary cavity seems to imply that the body was habitu- 

 ally submerged. The articular ends, which might be expected 

 to yield uselul characters, are not preserved. A communication 

 from Mr. Brodie opened the question of the extent and classifi- 

 cation of the RhDstic beds. The interesting discovery of these 

 deposits at Leicester formed the chief and most novel feature of 

 the discussion. Confident statement was on the whole more 

 conspicuous than matured reasoning in this part of the proceed- 

 ings of the Section, and much evidently remains to be done to 

 elucidate the palseontological and physical relations of the de- 

 posits in question. For the moment the preponderance, at least 

 of authority, rests with those who affirm the universal spread of 

 a Rhcetic age, and look in every quarter of the globe for a bone- 

 bed with Ceratodus and an Avicula-contorta zone. 



A large audience assembled to hear Dr. Carpenter's paper on 

 the red clay found by the Challenger, The substance of his re- 

 marks has already appeared in the Proceedings of the Royal 

 Society. 



The greater part of Tuesday's sitting was occupied by papers 

 and discussion upon the Glacial Period. By this time the easily 

 observable glacial phenomena have been co-ordinated, and there 

 is not quite so much room as formerly for supposition and uncon- 

 nected lacts. The discussion elicited a few curious points, and 

 was interesting, if not particularly instructive. Most readers of 

 such modern summaries as are given in Lyell's " Principles" or 

 Geikie's " Ice Age" would demur to the too sweeping language 

 in which the Chairman summed up the argument. Dr. Wright's 

 opinion that no man living knows anything of the Glacial Period 

 may possibly be just, but it _is not sulficiently incontestable to be 

 enunciated excathedrd. The most novel pomts of Dr. Carpenter's 



communication upon the "Sea Bottom of the North Pacific" were 

 the low temperature of the water at great depth=!, and the sup- 

 posed existence of coral reefs, drowned by too rapid submergence, 

 upon all the submarine summits. The species are believed to 

 be recent, and the submergence comparatively modern. Some 

 notice was taken of the results obtained by the Valorous, and of 

 Mr. Gwyn Jeffreys' view that the Arctic shells of the Sicilian 

 Tertiaries were derived from polar areas by migration through a 

 marine gap not far distant from the present canal of Languedoc. 

 Mr. Thomson's views as to some new genera of fossil corals, 

 which met heavy criticism at the Geological Society, were 

 brought up once more here, but gained no support of conse- 

 quence. The method of investigation is curious, but it has 

 hitherto proved somewhat barren of results. 



Among other good papers may be cited Prof. A. II. 

 Green's account of the Millstone Grit of North Derbyshire 

 and South Yorkshire. This was a highly- condensed statement 

 of the stratigraphical relations of an extensive group of very 

 interesting rocks. The variations in thickness of the different 

 grits were referred to inequahties of the old sea-floor upon 

 which they were accumulated, hollows permitting a greater 

 thickness to form. Had discussion been allowed, it would have 

 been interesting to notice the remarks thrown out by those 

 classifiers of strata who regard the formation of every rock as a 

 definite and almost universal event in the earth's history. Rarely 

 has a better example been given than this of the local conditions, 

 often quite trivial in themselves, which regulate the extent, divi- 

 sions, and thickness, as well as the mineral and fossil characters 

 of a large formation. 



SECTION D. 

 Biology. 

 Opening Address by Dr. P. L. Sclater, M.A., F.R.S., 

 F.L.S., President.* 

 v.— NEOTROPICAL REGION. 

 The Neotropical Region is, I suppose, on the whole the 

 richest in animal life of any of the principal divisions of the 

 earth's surface. Much work has been done in it as regards 

 every branch of zoology of late years, and I must confine my- 

 self to noticmg the most recent and most important of the 

 contributions to this branch of knowledge. 



I believe the following t to be altogether the .most natural 

 sub-divisions of the Neotropical Region, which are nearly as 

 they are set forth in Hr. v. Pelzeln's " Ornithology of BraziL" 



1. Central American Sub-region, from Southern Mexico to 

 Panama. 



2. Andean or Columbian Sub-region, from Trinidad and 

 Venezuela, along the chain of the Andes, through Columbia, 

 Equador, and Peru, down to Bolivia. 



3. Amazonian Sub-rigion, embracing the whole watershed of 

 the Orinoco and Amazons up to the hiils, and including also the 

 highlands of Guiana. 



4. The South Brazilian Sub-region, containing the wood- 

 region of S.E. Brazil and Paraguay and adjoining districts. 



5. The Patagonian Sub-region, containing Chili, La Plata, 

 Patagonia, and the Falklands. 



Besides these we have : — 



6. The Galapagos, which, whether or not they can be assigned 

 to any other sub-region, must be spoken of separately. 



I. The Central American Sub-region 

 was, up to twenty years ago, very little known, but has recently 

 been explored in nearly every part, and is perhaps now more nearly 

 worked out than any other of the above-mentioned sub-regions. 

 There is as yet no complete work on the zoology of any portion 

 of it, and the discoveries of Salle, Boucard, dc Saussure, and 

 Sumichrast in Mexico, of Salvin in Guatemala, of v. Frantzius 

 and Hoffman in Costa Rica, of Bridges and Arce and Veragua, 

 and of McLeannan in Panama, together with those of numerous 

 other collectors, are spread abroad among the scientific peri- 

 odicals of Europe and America. Even of Mexican zoology, 

 long as it has been worked, we have no general account. To 

 mention all these memoirs in detail would be impossible within 

 the limits of this address ; but I will say a few words about the 

 more important of them that have lately appeared. 



* Continued from p. 382. 



t A general sketch of the Mammal-life of this region is given in my article 

 on the Mammals of South America in the Quar. Jouni. of Science for 1865, 

 and a Summary of the Birds in Sclater and Salvin's "Nomenclatw Avium 

 Neotropicalium." 



