OF NEW SOUTH WALES. 429 



the late Rev. W". B. Clarke, in which he recapitulates his views 

 and controversies upon the Geology of the Sedimentary Deposits 

 of New South Wales. This little book is illustrated with four 

 sections and a map of a portion of the Illawarra and Hartley 

 coal-fields, embracing-, therefore, a large portion of the Hawkes- 

 bury and Waianamatta beds, and enriched by no less than twenty- 

 appendices of great interest, and some (xiv. — xvi., xviii., xx.) of 

 the highest importance. It is a fourth edition, very much en- 

 larged, of a small memoir published in the catalogue of the Pro- 

 ducts of New South Wales, prepared for the Paris Exhibition of 

 1867 ; and, owing to its gradual formation, and what may be 

 termed its " concretionary structure," is not an easy writing to 

 decipher. Mr. Clarke, beginning with the lowest sedimentaries, 

 mentions the Pre-Silurian only to question their development in 

 Australia, so far as is at present known, being apparently inclined 

 to believe that the phenomena which have been supposed to 

 indicate them are merely the result of alteration by heat, pres- 

 sure, molecular movement, and other cosmical forces, to whose 

 operations he has given the general name of " transmutation."* 

 And no Palseontological evidence has as yet been adduced for the 

 existence of any strata older than the Upper Silurian. Mr. C. 

 does not, of course, assert that these rocks do not exist, but that 

 it is impossible to determine them, without such a survey as alone 

 can ascertain the succession of Unfossiliferous strata, except in 

 the lucky cases in which they happen to be caught in juxtapo- 

 sition. Our Paleeontology, therefore, for the present, commences 

 in the Upper Silurian epoch, when warm, shallow, and probably 

 much divided seas surrounding, or embayed by, districts of 

 igneous activity, occupied a large portion of the globe space of 

 Eastern Australia. These waters swarmed with such organisms 

 as we are accustomed to call Silurian, identical, iu many cases 

 with well-known Northern species, and forcing upon the observer 

 the impression (which may, it must be admitted, prove illusory) 

 that they are upon the same Chronological as well as Biological 

 level. It is not as yet possible to subdivide the Australian beds 



* It is as well to notice that Mr. C. was in the habit of confining the use of the word 

 Metamorphism to the changes which have brought the special metamorphic rocks ol the 

 old geology to their present condition, and substituting in the case of all more recent beds 

 the convenient term, of Transmutation . 



