Vol. 50.] GEOLOGY OP BATHUEST (NEW SOUTH WALES). 113 



but the writer has found indications of a Pentamerus, probably 

 P. KnigMii. This fossil, P. Knightii, is also found in other parts 

 of the colony ; as at the celebrated Jenolan Caves, which are 

 situated about 50 miles E.S.E. of Bathurst ; at the Yarraugobilly 

 Caves, in the extreme «soath of the colony ; about Yass, and 

 elsewhere. It is, of course, a very well-known Upper Silurian 

 fossil in Europe, and its occurrence in New South Wales goes far 

 to stamp the beds in which it is found as of approximately the same 

 age. Mr. E.. Etheridge, Jun., believes that it characterizes a 

 particular horizon in this colony. 1 Should this prove to be the 

 case, the fossil will be very useful, by enabling us to correlate the 

 various beds of limestone, together with the beds interstratified 

 with them, at a large number of places. The other fossils at 

 Limekilns lead one to the same conclusion, and the limestone has 

 therefore been generally recognized as of Upper Silurian age. 



At Eockley, about 20 miles south of Bathurst, there is a blue 

 limestone much resembling that at Limekilns, but composed almost 

 entirely of eucrinite-stems. It will very likely prove to be of the 

 same age. 



The Silurian strata on the east side of Bathurst generally dip 

 eastward, although occasionally the dip changes to west owing to 

 folding. On the western side the dip is westerly, so that there 

 appears to have been a great anticlinal fold over what are now 

 the Bathurst Plains, which has been completely denuded away 

 from that area. One would expect in this case to find a repetition 

 on the west of the beds which occur on the east ; but, owing to the 

 great similarity of the different beds of slaty rocks, it is extremely 

 difficult to recognize outcrops of the same bed at a distance from 

 one another. The limestones would be more likely to be recog- 

 nizable, but unfortunately these appear to exist rather in lenticular 

 masses than in extensive beds, so that it is doubtful whether 

 much assistance will be obtained from them. 



Quartz-reefs are very common in the Silurian rocks around 

 Bathurst. Many of them are auriferous, but few contain enough 

 gold to repay working, although some of the richest alluvial 

 workings in the colony have been situated not very far away, as 

 at Sofala, about 25 miles N., and Hill End, 30 miles N.N.E., 

 where reef-mining has also been extensively carried on. During 

 the last year or two successful attempts to extend some of the old 

 workings have been made ; among other places, at the Napoleon 

 Beef, about 10 miles east of Bathurst. 



Veins, other than quartz, are not uncommon. They mostty, like 

 the quartz-reefs, follow the general strike of the country rocks and 

 appear to be interbedded with them ; and, as they have evidently 

 undergone much alteration, it is often difficult to say whether they 

 are intrusive, or have resulted from local changes in some of the 

 sedimentary beds. One such vein, at Glanmire, 10 miles east, is 

 seen under the microscope to have a matrix of quartz, crowded with 



1 'On the Pentameridse of New South Wales,' Eecords Geol. Surv. N.S.W. 

 vol. iii. pt. ii. 1892. 



