41 



affected by constant showers of scoriae, and heated by streams 

 of h'quid lava from the adjacent igneous centres, would, no 

 doubt, undergo great change, such as already described. 

 While such a large surface of the water acted upon by winds 

 would heap together upon its shallow banks and shores, its own 

 water- worn fragments together with the re-arranged detritus 

 of a former period ; and away beyond these shallows towards 

 the outlet to the sea it would bear the finer particles of scoriae 

 sand, mud, and carbonaceous matter which forms the lignites 

 and the four to five hundred feet of laminated clays and sands 

 upon which the town of Launceston is built. 



It is evident from the contents of the latter beds that around 

 the margin of this vast lake a rich vegetation still continued 

 to flourish, notwithstanding the activity of the surrounding 

 igneous centres, and it is also evident, from the following cir- 

 cumstance, that the deposition of the Launceston bed took 

 place very slowly. These beds are composed of fine clay and 

 tufaceous sand, and they are for the most part separable into 

 very fine laminations. 



Between the laminated clays and sands, however, and form- 

 ing a direct chain through the whole series, occur thin beds of 

 fine blue clay, in which there is little indication of horizontal 

 lamination. They contain the remains of water plants which 

 grew in situ while the fine mud was being formed into clay 

 around them. 



That these water plants grew vigorously and in great abun- 

 dance is proved by the fact that the leaves falling elsewhere 

 in myriads upon the lake bottom, are never found to penetrate 

 this subaqueous thicket. Fragments of branches and twigs 

 occur among these plants abundantly, being heavy, but the 

 feathery leaves would be too light to penetrate their tortuous 

 branchlets, and would thus become speedily decomposed,|being 

 ■unprotected by a muddy envelope. 



The type of leaf most abundant in these beds, appears to 

 be a kind of elm. {See Fig. 1.) 



Although there are plenty of other forms like to the leaves 

 of maple, laurel, plane, and coniferous trees, ferns of Lyco- 

 podon are also well represented. (See Figs. 1 to 10 inc.) 



Of the fauna I have not been fortunate as yet in obtaining 

 any trace, with the exception of two or three JJnios, picked up 

 further north. {Fig. 2.) 



The carbonized tissue of various woods occurs abundantly 

 in some beds of clays together with the well-defined structure 

 of the bark of large trees composed principally of the oxide of 

 iron. This presents a large field for the palseontological 

 microscopist. I am sure valuable information would be 

 yielded to science were these beds to be minutely investigated. 



