522 A. 8. Woodward— Fossil Fishes of N. 8. Wales. 



to the extent of substituting arid deserts for marine areas, and 

 lengthy rivers for isolated shoals." 1 



The author points out that the fountain-head of all the misunder- 

 standing about waves among practical men has been Scott Russell's 

 error in assuming that oscillating sea-waves are converted into 

 waves of translation on running through shallow water over a 

 shelving bottom. 2 Mr. Hunt's experiments show that oscillating 

 waves, after traversing a gentle gradient, plunge seawards of the 

 water margin ; and he maintains that erosion by plunging waves 

 often extends far seaward of low-tide level. Indeed erosion by 

 the wave-currents of the heaviest oscillating waves extends with 

 diminishing intensity to a depth of at least 40 fathoms. 3 



The observations of the author on the combined action of waves 

 and wind-formed currents in removing and accumulating shingle 

 are of considerable interest and importance, affecting as they do our 

 knowledge of the beach-forms of the present day, and of the agents 

 that produce and modify them. H. B. W. 



III. — Memoirs of the Geological Survey of New South Wales. 

 Palaeontology, No. 4. The Fossil Fishes of the Hawkesbury 

 Series at Gosford. By Arthur Smith Woodward, F.Z.S., 

 F.G S. 4to. pp. xiii. + 55; with ten Plates and two Geological 

 Sections. (Published by Chas. Potter, Sydney, New South 

 Wales, 1890.) 



IN consequence of the discovery of some fossil fishes in the 

 Hawkesbury Series at Gosford, New South Wales, the fossil 

 collector of the Geological Survey was set to work in the quarry, 

 with the result, that a fine series of nearly four hundred specimens 

 was obtained ; and the present memoir is a detailed description of 

 the species by Mr. A. Smith Woodward, of the British Museum 

 (Natural History), Cromwell Road, S.W. 



The geological age of the Hawkesbury Series is not satisfactorily 

 settled, although generally considered to belong to the Trias. It 

 was hoped, therefore, that the fortunate discovery of these fishes 

 would throw much light on the stratigraphical position of a very 

 unfossiliferous set of beds, and this hope has not been disappointed. 



Some account of the rocks exposed in the Gosford quarry is given 

 in a preliminary note, by Mr. T. W. Edgeworth David, of the New 

 South Wales Geological Survey, who, judging chiefly from bore- 

 holes in the district, is of opinion that about 2462 feet of strata 

 intervene between the beds containing the fishes and the Coal- 

 measures. This description is accompanied by a geological section 

 of the quarry, and a vertical section of the beds found in the 

 neighbourhood, showing the position of the " Sandy Shale " and 



1 " The Evidence of the Skerries Shoal on the Wearing of Fine Sands by Waves," 

 Trans. Devon. Assoc. 1887. 



2 On the Action of Waves on Sea-Beaches and Sea- Bottoms, Proc. Boyal 

 Dublin Soc. vol. iv. pp. 241-290 (1884). 



3 Denudation and Deposition by the Agency of Sea- Waves, experimentally con- 

 sidered. With Preface: " The Story of a Besearch." Privately printed, 1889. 



