336 AUSTRALIAN, SOUTH AFRICAN, AND INDIAN COAL-MEASURES, 



shores of Port Jackson or in the gullies of the Blue Mountains. 

 The vegetation is also so similar that it is only bv a kind of 

 effort that one remembers that the formation is not the same." 

 I think this passage is an amusing though rather humiliating 

 illustration of the manner in which preconceived ideas may lead 

 to the misinterpretation of obvious phenomena, even when they 

 have been correctly observed. 



The sequence of these formations appears to be as follows : — 

 The Newcastle beds are succeeded by a blank in the record, 

 indicating a period of unknown length, during which the G^ossop- 

 teris flora was entirely swept away, not by any sudden cataclysm, 

 we may be su^e, but by the gradual alteration of climatic con- 

 ditions. It may very probably have been a period of depression 

 corresponding with an actual glacial period in higher southern 

 latitudes, and contemporaneous with the formation of the Bacchus 

 Marsh conglomerates, of which more hereafter. 



To the same period the Esiheria shales of 500 feet in thickness, 

 proved by Mv. David, may perhaps belong. And the con- 

 glomerates of Lake Macquarie, Murru^'undi, Wingelo, (?) &c., which 

 rest upon the greatly denuded coal measures, may probably form 

 the commencement of the new record. 



The Clarence Eiver series succeeds with its lower members, as 

 at Narrabeen, ove) laid somewhat irregularly by the great fluviatile 

 deposits known as the Hawkesbury sandstone (Sydney sandstone 

 of Dana and Jukes), which a\e thus intercalated in the Clarence 

 River series, and contain Thinnfeldia odontopteroides, Alethop- 

 feris Australis, and Odontopteris raicropliylla^ but no ToRniopleris 

 Daintreei. Large numbers of Ganoid Fishes, and two or 

 three species of Labyrinthodonts, Mastodonsaurus (?) and Platyceps 

 Wilhinsonii (P.L.S. N.S.W., 1886) have recently been added 

 to the known fauna of these beds, and, more remarkable still, 

 Tremanotus Maideni, a Bellerophontid mollusc, with siphonal 

 openings along the keel, has been described by Mr. Etheridge 

 from Cockatoo Island, where it was found in association with 



