33 



To the south, south-west, and south-east of Muddy Creek, the 

 tertiary beds crop out in various places, as at Branxholme, 

 Arrandoovong Creek, Byaduk, Lake Condah, Mount Eccles, 

 Hey wood, Bessiebelle, Portland, &c., and it may therefore be 

 affirmed with tolerable certainty that the formation is continuous 

 at no great depth below the surface right down to the coast. 

 From the various localities mentioned, fossils have been obtained, 

 many of which I have examined. Between the Grange Burn 

 and the sea, several lava flows, more recent than any of the 

 tertiary deposits, conceal the sedimentary strata, but when wells 

 have been sunk, a layer of shells has usually been met with at a 

 moderate depth. 



On the east of the Muddy Creek beds, the country is so com- 

 pletely covered by lava, that the underlying strata are invisible, 

 and I can ofier no opinion as to the extension of the tertiaries in 

 that direction. 



The shell deposits of Muddy Creek are seen in some places at 

 a considerable height above the surface of the water, but in 

 others, they appear to sink quite below the bed of the stream, 

 and thus become invisible, reappearing perhaps at the next bend, 

 high up on the bank. The difference in the level of the fossil 

 sections is no doubt due, in a great measure, to the action of the 

 creek itself, which, after working its way through the superin- 

 cumbent basalt, and thus reaching the tertiary strata, has eroded 

 them also, carrying away the more friable portions, and leaving 

 minor depressions in their surface, which, in the course of time, 

 have been filled up by the loose soil and boulders washed down 

 from above. The gently sloping banks on the shores of Muddy 

 Creek, where no fossil beds are in sight, have probably been 

 formed in this way. 



In one place, however, this stream flows over a mass of basalt 

 in its bed, forming a miniature waterfall, and here the igneous 

 rocks must be in their original position, which is a good deal 

 below the level at which they are found, when seen in contact 

 with the fossil outcrops close at hand, and their presence at such 

 a depth can only be accounted for by supposing that the sedimen- 

 tary deposits had been hollowed out prior to the igneous outflow. 

 It should be noted that the tertiary strata are horizontal, not 

 only at Muddy Creek, but throughout the whole of the district, 

 so that any irregularity of their surface can only arise from 

 denudation. 



II. The rossiLiFEROus Beds. 

 In both the Muddy Creek and Grange Burn sections, the shells 

 are usually embedded in argillaceous and calcareous bands, the 

 colour of which varies a good deal, the former having often^a 



