338 GEOLOGY AND PETROLOGY OF THE GREAT SERPEXTIXE BELT OF X.S.W., 



these as follows: — "The first is represented by a single specimen about four imlu's 

 in either dimension ; portion of a large stem of gymnospermous wood. The 

 ••ellular structure shows no sharp definition ; the tracheids may lie made out rather 

 vaguely, and these are traversed by numerous medullary rays, some of w'hieli ai'e 

 several cells in width, others only a single cell. Vague indications of bordered 

 pits appear in the tracheids, but on account of the poor definition of the tracheids 

 themselves, it is impossible to determine how many rows of these are present on 

 the tracheid. From the evidence of their more or less circular outline as seen on 

 the radial wall, one is inclined to the conclusion that there is only a single row of 

 these in each tracheid. The length of a single tracheid cannot be defined." 



The second form is illustrated by two specimens possibly originally united; 

 the one has roughly the appearance of a portion of a stem about five im-hes in 

 diameter, though really a bundle of parallel roots, each 5 to 8 nun. in diameter, 

 the other shows its fascicular nature more evidently. The tissues are preserved 

 in a red jasper, and dusty haematite considerably obscures tlie structures. "The 

 cellular structure has been (|uite disintegi'ated. There" is a solid core of woody 

 tissue traversed by innumerable medullary rays that run almost from the very 

 centre to the cortex, traces of the latter being ciuite evident (see Plate x.\i., figs. 

 11. 12). All trace of protoxylem seems to have been destroyed. There appears 

 no sign whatever of annular rings, though the secondary wood is of considerable 

 thickness, the average radius of the roots l)eing 6 — 7 mm. There is no trace of 

 pith structure. The secondary wood starts abruptly upon an indefinite mass 

 showing no cellular structure, but which we may interpret to be at least the jiosi- 

 tion of the phloem, the entire phloem having been replaced by silica. An out- 

 standing feature of the secondary xylem is the apparent uniformity of its cellular 

 structure. If its elements are tracheids, which seems to be the case, they appear 

 to be uniform in their size and structure from the position of tlie phloem to the 

 cortex. From the longitudinal section all traces of bordered pits liave been com- 

 pletely obliterated. To what gi-oup of plants these roots belong it would lie diffi- 

 cult to say until further evidence is obtained as to the detailed structure of tlieir 

 protoxylem and other tissues." The slides are in the collection of the Univevsitv 

 of Sydney. 



Mr. riiapman describes, in the aiijiendix. the occurrence of Oirraxelhi in tlie 

 oolitic limestones of the Parish of Babbinboon. 



The marine fossils of the Burindi Series so far obtained from the Turra- 

 bubnla, Somerton, Carroll ;ind Babbinboon Districts comprise the follciwing 

 forms : — 



COELENTERATA. 



Zaphrextis (Plerophyllum) crLLEXi Eth. fil. 



Mem. Geol. Surv. N.S.W.. Pal. No. 5. pt. 1. 1891. p. 13, I. 0. f. 1-7. 



This form occurs rathei' abundantly near the railway cutting Un\r miles east 

 of Currabubula. Collected by Benson. 



Zaphrextis simpiivexs Eth. fil. 



Mem. Geol. Surv. X.S.W.. Pal. No. 5. pt. 1. \i. 10. t. 11. f. 4-0. 



This form was described from the Somerton District; it also occurs in tlie 

 south-eastern portion of Babbinboon. Collected by Benson. 



