64 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [June 16, 
Gothlandica, Orthoceras, and stems of Encrinites*.’’ In another 
place+, another species of “‘ Favosites and Amplexus arundinaceus, 
and remains of Trilobites,”’ are mentioned as having been only at 
present noticed. 
In the year 1842 I discovered numerous casts of Trilobites on the 
right bank of the River Paterson, in a sandy micaceous mudstone at 
a spot called Burragood ; and in a concretionary limestone associated 
with brownish sandy shale, also concretionary, on the left bank of 
Binjaberri Creek, a feeder of the River Allyn. Since then I have 
found Trilobites in a rock of the same age, partly a pure limestone, 
partly a slaty clay, on the bank of the Allyn, at Colocolo near Ca- 
myrallyn, as well as near Trevallyn on the Paterson. . 
In 1846 I received from T. A. Murray, Esq., M.L.C., some frag- 
ments of a fossiliferous rock found at Yarralumla near Queanbeyan, 
and at Mount Murray, in the county of Murray; on breaking up 
which I detected several species of Trilobites, which can be referred 
to well-known Silurian genera. 
The Yarralumla rock resembles, in all respects, the Burragood 
mudstone, and, like it, contains concretionary lumps of a ferrugimous 
limestone surrounding fossils which are generally Trilobites. The 
fossils there, as well as at Burragood, are thickly coated with a 
powder of yellow oxide of iron. 
The direct distance between these localities is 230 miles. The 
site of the former is to the east, of the latter to the west of the great 
dividing range or Cordillera ; the former to the north-east of the latter. 
As the associated fossils in both places correspond, these discoveries 
serve to point out the fact that the same formations occur in similar 
geological order on both flanks of the older rocks comprising the 
Cordillera, at great distances. Yass Plas, where Strzelecki found 
traces of Trilobites, lie thirty-two miles N. by W. of Yarralumla ; 
and the ridge near Booral, north of Port Stephens, where he also 
found minute fragments of crustaceans belonging either to Cythere 
or Bairdia, in a caleareo-argillaceous flag-stone, is situated about 
thirty-two miles E.S.E. from Burragood. In these flagstones I 
found true Orthide in March 1842. M. Leichhardt has also re- 
marked that he found the same sequence of geological formations in 
descending to the shores of the Gulf of Carpentaria that he kad ob- 
served in ascending the ranges of the Cordillera along the Rivers 
Burdekin and Clarke. Little doubt, therefore, remains as to the 
persistency of the geological phenomena throughout the course of 
the Cordillera. From Yarralumla to the junction of the Burdekin 
and Clarke cannot be less than 960 miles of direct distance. A lime- 
stone was observed on the Burdekin containing small Spirifers resem-, 
bling those of Yass Plains, and Cyathophyllide. 
At Burragood the genera of Trilobites are chiefly Trinucleus and 
Asaphus. Mr. MacLeay has done me the honour of calling one of 
the former after its finder, 7. Clarke. 
Mr. Clarke then enumerates forty genera, with 240 species of 
fossils associated with Trilobites at Burragood. 
* P. 268. + P. 296. 
