Yol. 69.] THE STRUCTURE OF DADOXYLOX KAYI. 457 



Araucaria. The chief botanical interest of these specimens, how- 

 ever, lies in the fact that we have here further evidence of the 

 occurrence of Coniferse in the higher Coal Measures of the Midlands. 

 The leafy twigs of Wdlchia are very rare fossils in the British 

 Coal Measures, but they have been recorded by Dr. Kidston from 

 two or three localities in South Staffordshire. It is true that no 

 Buch shoots have been recognized at Witley, and there is at present 

 no direct evidence to correlate these woods with WalcMa. But 

 these woods were undoubtedly also Coniferous, though not neces- 

 sarily Araucarian, nor with certainty allied to WalcMa. 



These stems are perhaps of greater geological than strictly 

 botanical interest. It need hardly be pointed out that practically 

 all the petrified material known from the British Coal Measures 

 is derived solely from the calcareous nodules or ■ coal-balls ' of the 

 Pennine coalfields, and from Lower Coal-Measure rocks. The 

 exceptions can be counted on the fingers of one hand. There are, 

 it is true, the extraordinary breccia-petrifactions, as yet not fully 

 described, recorded a few years ago by Mr. Lillie 1 from the Transi- 

 tion Coal Measures of Bristol. Of greater importance in the 

 present connexion is Dadoxi/lon spenceri Scott," from the Lower 

 Coal Measures of Halifax, which occurred as an isolated petrifaction. 

 This is, I believe, the only other species of this genus hitherto 

 recorded from Britain, and it is quite distinct from that which is 

 described here. 



The occurrence of isolated petrifactions, free from any calcareous 

 matrix, in the Lutley Yalley is interesting geologically, because on 

 the Continent, especially in the Permian rocks, such trunks are of 

 frequent occurrence. In this country the conditions necessary for 

 the preservation of woods in this manner appear to have recurred 

 but rarely. I do not propose to enter here into any comparison 

 with the fossil woods of the Permian rocks of Germany, described 

 by Goppert and others. Attention may, however, be called to the 

 remarkable fossil forests of the beds of that age in the neighbour- 

 hood of Chemnitz, in Saxony, the relics of which have been so 

 carefully preserved and described by my friend Prof. Sterzel. 3 Most 

 of these woods resemble D. Icayi in type, and belong to the same 

 genus. 



Dadoxylon "kayi, sp. nov. 



Diagnosis: — Pith very small, not discoid. Wood without true 

 rings of growth, tracheides small, 0*037 to 0*051 mm. across, dense, 

 long, with one to three alternating series of bordered pits on the 

 radial walls. Medullary rays very abundant, uniseriate or some- 

 times incompletely biseriate, varying from one to twenty-seven cells 

 in height (0*06 to 0*66 mm.). 



1 D. G. Lillie, Geol. Mag. dec. 5, vol. vii (1910) p. 60. 



2 J). H. Scott, Trans. Roy. Soc. Eclin. vol. xl, pt. 2 (1902) p. 357. 



3 J. T. Sterzel, xiv. Bericht Naturwiss. Gesellsch. Chemnitz (1896-1900) p. 3, 

 and xv. Bericht ibid. (1900-03) p. 23. 



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