ANNIVERSARY ADDRESS OF THE PRESIDENT. 



59 



series of schists, alternating with bands of purplish slate, and 

 are believed by Dr. Hicks to bo of Pebidian age : the strike is from 

 N.E. to S.W. 



Between Caen Cochion and Pen-maen east of Traws-fynnyld road, 

 the Cambrian conglomerates are seen resting unconformably upon 

 tho older series ; and masses of the Pre-Cambrian occnr plentifully 

 hi the conglomerate. It is to be hoped that Dr. Hicks will continue 

 his researches over this wild and difficult region ; it is highly im- 

 portant to know the precise nature of the axis and underlying rocks 

 of the anticlinal. The researches of Professor Ramsay and the 

 Survey detail all that we really know of the great mass of the 

 Harlech Dome or Merioneth anticlinal*. Caernarvonshire, Angle- 

 sey, Shropshire, the Malvern Hills, and Scotland have received critical 

 examination from Dr. Hicks ; but his results are too full of detail to 

 be entered upon here. 



The physical structure and life-history of the classical promon- 

 tory of St. David's has of late years, at the hands of Salter and 

 Hicks, received an amount of research and attention of which 

 scarcely any other district can boast. 



The rocks composing the ancient headland of Menapise are, 

 perhaps, the oldest known rocks containing organic remains in the 

 British Islands, if not in the world ; nevertheless the characters 

 presented by the contained organisms are such that we cannot 

 imagine that we have here traces of the earliest manifestations of 

 life upon the earth. 



In treating of the various successive formations embraced in the 

 recognized Palaeozoic divisions of the British sedimentary rocks, 

 I shall omit altogether any definite classification into great systems. 

 For while we may define one period as characterized by the 

 presence of a certain fauna, which in the next succeeding so- 

 called epoch, is replaced by a different one, there will always be 

 found in some part of their geographical distribution a region 

 where, in some form or condition, the two faunas commingle, 

 and where the old one gradually disappears as the new one comes 

 in or makes its appearance, To assign, therefore, any definite or 

 precise boundary-lines or limitations to our stratified rocks and their 

 contents, when the record of past life is of necessity so incomplete 

 and obscure, is, to say the least, at present premature, if not unphi- 

 losophical, however convenient it may to a certain extent be ; but 

 the progress of so boundless and progressive a science as Geology 

 with its associated subjects, demands that we should lay clown no 

 hard or definite lines, no brackets or definitely constructed tables. 



Each year witnesses the breaking-down of arbitrary divisional 

 lines in classification, in Zoology and Palaeontology as well as in 

 Geology. Any attempt, therefore, to establish geological divisions 

 or horizons upon either stratigraphical or palaeontological breaks 

 must be temporary and local only ; probably there exists no 

 break in life, any more than in time or in sedimentation ; for some- 



* Vide Ramsay, Mem. Geol. Survey of Great Britain, yol.iii. Geol. of North 

 Wales, pp. 17-19. 



