173 



visited the bore. I am, therefore, unable to express an opinion as 

 to the nature and probable age of the intervening portion of the 

 section ; moreover, I had not the opportunity of examining any 

 of the extracted material. Particular interest, as regards this, 

 geological section, belongs to the fossiliferous sands extending in 

 depth from 320 to 410 feet ; because, if I have rightly correlated 

 the fauna here brought to light, we have now knowledge of a 

 marine deposit of Pliocene age, which partially fills the hiatus 

 separating our Older Tertiary series from the Pleistocene and 

 Recent Marine formations. 



The sand is very sharp and somewhat coarse ; it resembles- 

 broken quartz-crystals, and shows little or no attrition. With it 

 there is freely mingled dark-brown or blackish carbonaceous chips, 

 apparently belonging to stout stalks of sea-weed ; the dissolved 

 sulphurretted hydrogen in the outflowing water may have origi- 

 nated partly from the chemical action of the decomposing vege- 

 table matter on the alkaline sulphates, whilst some of the animal 

 tissues, which in the form of the ligamental union of bivalve- 

 shells is still preserved in some of the larger species, may have 

 contributed in a like manner. The organic debris consists largely 

 of broken shell-substance ; whilst the more or less perfect shells, 

 which also show no signs of extensive rolling, have lost their 

 original lustre ; though in one species of Phasianella traces of 

 colour are not infrequently clearly discernible, though the original 

 polish has been wholly obliterated. The presence of quartzite- 

 pebbles at from 400 to 410 feet would indicate an approach to 

 the base of the Tertiary series ; the pebbles range to about one 

 inch in diameter, and are only slightly eroded. 



The fauna comprises 10 species of foraminifera, a coral (Cyclicia 

 rubeola, Q. & G.), a few species each of Crustacea (Miminius 

 simplex, Darwin, &c.), echinoids ( Goniociclaris, sp., Stronglyocen- 

 trotiis, sp.), and polyzoa, 60 species of lammellibranchs and 150 

 gastropods. The species have been carefully compared with 

 Recent and Tertiary forms belonging to Australasia, and less 

 exhaustively with Recent and Tertiary faunas of exotic areas ; 

 with the general result that about one-half of the species is pecu- 

 liar, about 30 per cent, common to the Miocene fauna as known 

 at Hallett's Cove and southward to Aldinga Bay, at Muddy 

 Creek and at the Gippsland Lakes, whilst about 20 per cent, 

 belongs to the recent fauna of Southei-n Australia. This result 

 would not be anticipated from a cursory survey of the collection, 

 which has a strong modern facies, though the majority of the 

 species after careful comparison prove to be distinct. 



Details of the result of a comparison of the Lamellibranchiate 

 fauna with those of the Recent and Tertiary Epochs I am able 



