BY R. ETHERIDGE, JUN. 213 



Conclusion. — It has been shown that throughout the Pindan 

 Sands and Gravels, there protrude isolated hills and ridges, 

 which were believed by Hard man, from their associated fossil 

 plants, to be Carboniferous. Ironstone Kidge is evidently a similar 

 hill, and not a portion of the Pindan Series at all, the latter resting 

 on the flanks and filling up the hollows between the Carboniferous 

 prominences. This view is, I believe, borne out by an expression 

 of Hardman's, to the ejffect that " about ten miles south of the 

 Yeeda station it" (i.e., the Pindan,) "is 30 feet thick, and rests on 

 coarse sandstone, probably of Carboniferous age."* Here we have 

 the sandstone forming the bed-rock, and it is of course possible 

 that it may extend under the Pindan deposits, where denuded 

 away before their deposition. That the fossiliferous beds at 

 Ironstone Ridge form a portion of the Upper or Sandstone Series, 

 is again borne out by the fact that further south in the Fitzroy 

 district, the place of the plants in this sandstone is taken by a 

 copious marine fauna, f This point is an exceedingly interesting 

 one, for again further south, a similar fauna has been shown to 

 exist in the basin of the Gascoyne Hiver, by Mr. W. H. HudlestOxi,i 

 the fossils of the two areas having a close resemblance to one 

 another. 



As regards Mount Marmion, we have here a repetition of what 

 takes place in the Fitzroy River district, the appearance of a 

 marine fauna, in beds forming a portion of Hardman's Upper or 

 Sandstone Series. 



The conclusions which may be drawn from a study of these 

 fossils from near Derby are briefly the following : — 



(1) The Pindan beds may still, for all that is known to the 



contrary, be regarded as of Tertiary age. 



(2) The Ironstone-ridge at Yeeda station cannot be regarded 



as of the age of the Pindan Series, but is of a similar 

 Carboniferous facies to Mount Marmion, &c. 



* 1st Report, 1884, No. 31, p. 8. 



t 2ud Report, 1885, No. 34, p. 16. 



X Quart. Journ. Geol. See, 1883, XXXIX. p. 582. 



