Displayed in the Fisherman's Bend Gutting. 167 



average depth below low-water mark of this upper 

 limit of the clay is 16 feet. The bed of the canal is 4 feet 

 lower, and the clay was still found to be present in a channel 

 cut 11 feet deep in the floor for the passage beneath the canal 

 of the Yan Yean main water-pipe. How much deeper the 

 clay extends is not known^ but it has thus been traced for 

 15 feet. No animal or vegetable remains have been found in 

 this clay, but Mr. Davies informs me that he has obtained 

 nodular concretions at one point. 



There is, as we have said, one remarkable exception to 

 the general uniformity of level in the surface of this 

 unfossiliferous clay. This occurs in the form of a linear 

 depression stretching across the canal near the east end. 

 As seen in the floor of the canal, the sharply-defined borders 

 are two parallel lines running across the floor, with a trend 

 N. 80 degs. W., S. 30 degs. E., and making an angle of 

 45 degs. with the banks of the cutting. The perpendicular 

 distance between the borders is 200 feet, and the distance of 

 the centre of the parallel band from the east extremity of 

 the canal 550 feet. As seen in the sides the sections of 

 the depression are gently sloping curves of slight concavity. 

 This hollow is filled with the black silt, and the shell-layers 

 dip into it with a corresponding curvature. It is evidently, 

 I think, an old channel of the Yarra, or of one of its estuarine 

 branches. 



Above the clay lies a thickness of about 7 feet on the 

 average, increasing to 10 or 12 feet towards the east end, of 

 blue-black silt, of estuarine origin. The lowest stratum of 

 this silt, resting on the clay conformably to the curvature of 

 its very moderately undulating surface, is a remarkable 

 layer of about 15 inches average depth, crowded with 

 marine shells, all of species still to be found in the Bay. 

 Near the surface of junction a tbin layer forms a conspicuous 

 white band, which, as one stood on the summit of one bank 

 of the canal, could be traced readily by the eye, extending 

 throughout the visible portion of the opposite slope. The 

 usual thickness of this band was 3 inches, but in some 

 places it divided into two, or even three, branches; but these 

 were exceptional, and never occupied a greater thickness 

 than a few inches. It was composed of thousands of speci- 

 mens of Area trapezium (Desh), with a large number of 

 oysters, 0. edulis. Both species assuredly lived on the spot, 

 as evidenced by the greater number occurring with the two 

 valves united, and by the presence of multitudes of indi- 



