Vol. 55.] ox PALEOZOIC EADIOLAKTAI^ ROCKS IN N. S. WALES. 17 



A collection of specimens of the radiolarian limestone was 

 forwarded to Dr. Hinde for specific description. The Second Coral- 

 boring Expedition to Punafuti last year somewhat delaj'ed the 

 collecting of further evidence, though the discovery was made (by 

 E. F. Pittman) that LepidocUndron australe occurred in situ in the 

 radiolarian series. At the beginning of this year (1898), however, 

 we were enabled to pay three short visits to the locality, and 

 found that radiolaria were by no means restricted to the thin bands 

 of lenticular siliceous limestone, but were distributed in numbers 

 so vast throughout the jointed clay stones (the prevalent sedimen- 

 tary rock in the district) as to constitute perhaps half their bulk. 

 The thickness of the whole Eadiolarian Series was estimated at 

 about 9260 feet, inclusive of the submarine tuffs. The discovery 

 that so enormous a thickness of Palaeozoic rocks, previously con- 

 sidered to be either unfossiliferous or to contain fossils only at wide 

 intervals, has been built up very largely of tests of radiolaria, is 

 obviously of considerable interest from the stratigraphical as well 

 as from the palseontological point of view. 



II. Localities. (See Map, PI. II.) 



(1) Bingara. — The farthest point north to which radiolarian 

 rocks have as yet been traced in ISTew South Wales is a spot on 

 the Keira road, about 3 miles east of Bingara. These strata were 

 examined by Mr. Gr. A. Stonier, F.G.S., and one of us in 1890, 

 and the first radiolarian casts were observed in some thin sections 

 of these rocks, prepared at the University of Sydney some years 

 later. 



(2) Barraba. — This locality is about 30 miles south of the pre- 

 ceding, and 60 miles north of Tamworth. 



Radiolarian casts have been observed in thin slices, prepared as 

 above from specimens of jasper collected here by Mr. G. A. Stonier 

 and one of us. 



(3) Tamworth. — The locality where the radiolarian rocks, in 

 this neighbourhood, appear to be most abundant is near the southern 

 extremity of Tamworth Temporary Common, at the quarry shown 

 in PI. YII. Radiolarian rocks have, however, been traced by the 

 authors from the point marked 10, in PI. Ill, to the garnetiferous 

 limestone in the same section, a distance of 3 miles, measured from 

 west to east. They are also well shown in cuttings of the Great 

 jN"orthern Railway south-east and east of Tamworth, between the 

 185- and 190-mile posts. Korthward they have been traced con- 

 tinuously to Moor Creek, a distance of 6 miles. There can be 

 very little doubt, however, that the belt of radiolarian rocks is 

 continuous from Tamworth through Barraba to at least as far north 

 as Bingara, a distance of 85 miles. 



(4) Jenolan Caves. — This locality is situated about 67 miles 

 due west of Sydney, and about 200 miles south by west of Tam- 

 worth. The radiolarian casts occur there in vast numbers, chiefly 



Q. J". G. S. No. 217. c 



