368 Dr. a. Hicks — Life Zones in Palceozoic Rocks. 



As to the coarser detrital material of the Banter, which clearly 

 gives us a record of conditions very different from the lacustrine 

 conditions under which the Keuper marls were deposited, I have 

 never been able to see how a riverine origin for these coarse and 

 irregular deposits can be reconciled either with their structure, their 

 composition, or their geographical distribution. There are plenty of 

 sections in and around Nottingham (Castle Eock, Church Cemetery, 

 Sneinton, and other places) where these structural characters may 

 be studied. More recent work has but confirmed the view I put 

 forward twenty years ago as to the rocks of the Pebbly Sandstone 

 type (such as we have in Notts) consisting of Triassic sandbanks 

 deposited in narrow tidal seas ; and more extended observation of 

 the gi-eat pebble-beds of the Warwickshire and the Budleigh 

 Salterton type, compels me to regard them as the " chesil-banks," 

 which formed the shore-equivalents of the sandbanks. 



YI. — On some Life Zones in the Lower Paleozoic Eocks of 

 THE British Areas, as defined mainly by Eesearches during 

 THE Past 30 Years. 



By Henry Hicks, M.D., F.R.S., F.G.S. 



IT not unfreqnently happens in these days of superabundant 

 scientific periodical literature that articles appear in which tlie 

 authors, usually unwittingly, and generally from want of leisure, 

 fail to give an adequate idea of the work of authors anterior to 

 periods with which the writers are more specially acquainted. 

 The injustice thus perpetrated can best be prevented by giving 

 occasionall}' a brief resume of work done in certain formations and 

 in special areas during a given period. The present time seems 

 to me appropriate for giving such a resume in the Geological 

 Magazine. The first Number of the Geological Magazine was 

 published exactly 30 years ago (July, 1864), and in articles in the 

 first Number by two eminent palseontologists (Prof. E. Jones, the 

 then Editor, and Mr. J. W. Salter) we have clear and definite 

 statements relating to the advances which had been made, and to 

 the prevailing influences aftecting geological thought at that time. 

 The writings of Edward Forbes, Darwin, and Huxley were then 

 producing a marked 06*601, and workers were led to search more 

 carefully than had ever been done before for causes which may 

 have tended to influence the distribution of life in the past, and 

 many of the methods of research now in use are the outcome of the 

 advances then made. It was undoubtedly a period marked by great 

 changes in methods of research, but, fortunately, facts which had 

 been well established and the means by which they had been 

 obtained were not forgotten. The general effect was well described 

 by Prof, Eupert Jones in the following passage in the Editorial 

 Article, Yol. I. p. 3, entitled " The Past and Present Aspects of 

 Geology": "It is now rightly considered legitimate to call in the 

 agency of forces which, though not seen in operation in nature, may 

 be evoked in the laboratory ; and we thus seem to be in a fair way 



