These silicified fossils are only to be found at the base of the 

 beds, mostly fragmentary, but showing clearly all the beauty of 

 detail of the cell-structure of the Thinnfeldia leaves. 



BED B. This is a light-coloured volcanic tuff with much 

 ferruginous staining. One portion of the exposed bed contains 

 a large concretion of very ferruginous tuff, while irregularities are 

 to be observed between the tuff and the overlying shales. Changes 

 in the local conditions at the time have produced unevenness in the 

 deposition or distribution of the volcanic ejectamenta, and in the 

 irregularities thus produced the fine sediments forming the shales 

 have been quietly laid down. 



This tuff occurs as small outcrops at several other horizons 

 below this position and within a thickness of about 200 feet of strata, 

 its conspicuous character being a red coloxiration. This staining, 

 which is the red oxide of iron, has been leached out of the decom- 

 posing blue shales and is not an alteration product of the tuff, the 

 latter probably being trachytic or rhyolitic. The fossil leaf impres- 

 sions are sometimes completely coated with this bright red pigment, 

 which frequently fills in the minute spaces representing the thickness 

 of the original leaf, and occasionally colours the insects. The average 

 thickness of the bed is about two feet. 



Fossil leaves are not common in the tuff and are mostly confined 

 to species of Thinnjeldia. Rough impressions of this fern occur in 

 the top portion of the bed close to the shales, and here is also to be 

 observed a layer of what might be termed a charcoal breccia made 

 up of particles of previously b'M-nt wood enveloped in a coarse- 

 grained tuff. 



BED C. This is a bed of shale about a foot thick, somewhat 

 decomposed and iron-stained, in part tuffaceous, and containing a 

 great number of indifferently preserved impressions of Thinnfeldia, 

 with Stenopteris, Ginkgo, Tceniopteris, Sphenopteris, and many other 

 forms of less frequent occurrence. 



BED D consists of a three-inch band of hard blue shale, very 

 difficult to split, and much broken up by vertical jointings. Fossil 

 leaf impressions occur in it, but they are fragmentary and poorly 

 preserved. 



BED E. The fossil insect bed of finely arenaceous shale. 

 Near the outcrop the bed is of a brownish grey colour with iron- 

 stained joints and planes, and it is in this part of the bed that most 

 of the insect specimens were discovered. At the bottom of the quarry, 

 more particularly below the ironstone concretion shown in the 

 illustration (Plate 8), the bed is a greenish grey colour, and hero 



