404 NOTES AND EXHIBITS. 



been filled up with a pure white marl full of leaf impressions, 

 but too brittle to allow of any specimen being obtained from the 

 portions now exposed. In this marl are distributed nodules 

 of travertine, encrusting forms which appear to be partially- 

 decomposed portions of Favosites, but may turn out to be only 

 of mineral origin. A dyke of grey porphyry, with felspar 

 crystals much decomposed, runs through this limestone, and is 

 probably the cause of its bleaching and crystallization. Crinoid 

 stems, Brachiopods, and Petraia (PeiTaria) are seen in a fragment 

 which has been half burnt and subsequently weathered.* 



* This Limestone has been described by Professor Liversidge in his ' Minerals 

 of New South Wales/ p. 111. 



