Pliocene Strata on the Moorahool River. 83 



Hall, who at once said that they represented a new bed and not 

 the one he and Mr. Pritchard had described, which is on the 

 west side of the river. The shell casts were submitted to Mr. 

 Dennant last year, who said that they appeared to consist of 

 living species rather than of those proper to the Miocene, and 

 recommended me to send them to Professor Tate for definite 

 determination. This was done, and, with his usual good nature, 

 the Professor, whose recent death must be deplored by all of us, 

 wrote to me at some length upon the material forwarded. I give 

 Professor Tate's remarks in his own words : — " The majority of 

 the mollusca are in the state of pseudomorphs after calcite, and 

 the fine ornament in the majority of cases is obliterated ; this 

 renders critical comparison hardly possible. At a first glance it 

 seemed that the collection might belong to any period, from 

 Miocene to Recent. However, selecting the species shewing the 

 most determinate characters, I proceeded to ascertain their species 

 names, and, after comparison with related species, recent and 

 fossil, I arrived at the conclusion that I had essentially a modern 

 fauna to deal with. This gave me a clue to the determination of 

 the obscure forms, though in their case, as with the others, all 

 available sources of comparison were utilised. The result is that 

 of 13 species, to which approved names have been given,^ 12 are 

 recent species, and are to Ije found as cast-up shells on the 

 beaches of Southern Australia. The extinct species is Pecten 

 antiaustralis, which, however, extends from its commoner habitat 

 of Miocene to Older Pliocene ; it is one of the very few which 

 pass up from the Older Tertiary to just within touch of the 

 Recent. 



In conclusion, (1) The faunula is essentially recent, and, though 

 one out of thirteen is not actually known living, it would be 

 misleading to apply the percentage test on such low figures as an 

 index to age, and it is not improbable that, if the list were 

 extended to a hundred, 99 per cent, would be recent. The 

 deposit is synchronous with that of Limestone Creek described 

 by Mr. Dennant, and if from that faunula we subtract the species 



1 Four others were subsequently named by Professor Tate, and the list now contains 17 

 named species. 



