6 Excursion to Parwan and Coimadai. [vj^^xxxiii 



expanding, and that pools of water and piles of shingle occur 

 in some of them. In support of the contention that the caves 

 trend in the direction of the river, it is pointed out that an 

 opening similar to that by which we gained access to the cavern 

 occurs in a paddock to the north-east, and that a fox terrier 

 which was lowered into the cave visited by the party made his 

 exit by a hole in the right bank of the Werribee, fully a mile 

 and a half distant. The basalt would seem to rest on a thin 

 stratum of grit and pebbles, and this on limestone. The lime- 

 stone outcrops about half a mile to the south, on the property 

 of Mr. P. Wheelan, and has been worked to a limited extent. 

 A few hundred yards north a bore was put down in quest of 

 vvater, and passed through a deposit of lignite. Though no 

 limestone was noted, the cave may owe its origin to the long 

 and continued action of water on this soft and porous formation. 

 In a paper published in the Naturalist for February, igocj 

 (vol. xxvi., p. 157), I cited an instance that occurred at a spot 

 about two miles to the south-west of the caves, that would 

 seem to support the \'iew that beneath the Panvan basaltic 

 sheet there exist extensive subterranean ramifications through 

 which the surface water of the plains and from the Brisbane 

 Range and valleys to the north finds its way to the Werribee. 

 The party quitted the vicinity of the caves shortly after 

 10 o'clock, and, l)earing east, crossed the Werribee below its 

 confluence with the Parwan Creek and the Lerderderg, some 

 little distance above its junction with the former stream. The 

 flood-i:)lain hereabouts was carpeted with long, luscious grass 

 and shaded by large, spreading Red Gums, and from the hillside 

 presented a very pleasing asj^ect. Proceeding onwards at a 

 leisurely pace, we at length reached the Pyrete Creek, which, 

 before it junctions with the Werribee. flows through a broad 

 and fertile valley in a very narrow channel fully 20 feet in 

 depth. Huge Red Gums line its banks, and extend to where 

 the alluvial is succeeded by the less congenial Silurian shales, 

 when they are supplanted by the Red. Y'.'llow. and Grey Box, 

 the Manna and Yellow (ium, tire Bull Mallee, and the Moonah, 

 Melaleuca parviflora. Reaches of watei" occurred here and 

 there in the bed of the creek, but the party found the liquid 

 far too brackish for their liking. Owing to the lack of drinking 

 water, and to the iiigh temj)eraturc, such i)oor progress was 

 made that at \ o'clock, when still a few miles from our destina- 

 tion, it was decided to abandon the projected visit to Burnip's 

 Quarry, and repair to a neighbouring farm-house to assuage 

 our thirst. From here we made our way to the Lerderderg, 

 where we rested for an hour, and thence to the Bacchus Marsh 

 railway station, which we reached about 7 p.m., after a journey 

 of about twelve miles. The physiography of the district was 



