SILURIAN AND DEVONIAN ROCKS. tae 
( Pentamerus Knightii, var. striata 
| - Siissmilchii, sp. nov. 
| Anoptotheca (?) australis, . 
Brachiopoda < Meristina (?) australis, a 
| Atrypa, sp. ind. 
| Rhynconella, sp. ind. 
| Orthis (?) sp. ind. 
Crinoidea |§—Crinoid stems 
( Favosites 
Pachypora 
Actinozoa Heliolites 
\ Tryplasma liliiformis 
Several of the above are new to science and have been 
described by Mr. W. S. Dun, F.G.s.’ 
B. The Claystones (Slates)—These are similar in litho- 
logical characters to most of the so-called slates of Silurian 
age occurring in N. 8. Wales, and possess no features of 
special interest. They appear in places to be more or less 
tuffaceous and have numerous beds of tuff associated with 
them. The topmost bed (vide section) contains numerous 
rounded fragments of limestone and rhyolite, probably 
ejected volcanic material. No fossils were found in any of 
these strata. 
C. The Tuffs.—At the top of the Silurian formation, 
occurs a bed of coarse red tuff, 200 feet or more in thick- 
ness. It contains numerous red felspar crystals, but is too 
decomposed for microscopic examination. <A good outcrop 
may be seen in Gap Creek (Portion 98). Here numerous 
thinly bedded cherty shales occur interstratified with the 
tuffs in such an irregular manner as to give them the 
appearance of being intrusive. (Plate 16.) This occurrence 
is apparently similar to those described from Lyndhurst’ and 
Tamworth’ by Messrs. Davidand Pittman. Near the top of 
+ Rec. Geolog. Survey of N.S. Wales, Vol. vii1., part iii., 1906. 
? The Mineral Resources of N. S. Wales by E. F. Pittman, A.R.S.M., 
p. 53, “The Auriferous Ore-beds of the Lyndhurst Goldfield.” 
3“ On the Paleozoic Radiolarian Rocks of N.S. Wales,” by Prof. T. W. 
E. David, B.a., F.R.s. and E. F. Pittman, a.r.s.m.—Quart. Journ. Geolog. 
Soc., London, 1899. 
