81 



NOTES ON THE EELATIONS OF THE YELLOW 



LIMESTONE (TRAVERTIN), OF GEILSTON BAY, 

 With other 

 FLUVIATILE AND LACUSTRINE DEPOSITS IN TAS- 

 MANIA AND AUSTRALIA, 

 Together with 

 DESCRIPTIONS OF TWO NEW FOSSIL HELICES. 



By Robt. M. Johnson, F.L.S. 



[Bead 8tJi Sejjtemher, 1879.] 



The freshwater limestone in the neighbourhood of Geilston 

 Bay, Hobart Town, is most interesting to geologists on 

 account of the richness of its included organic remains. It 

 attracted the attention of the illustrious Mr. Darwin during 

 the visit of H.M.S. Beagle to Hobart Town, and was after- 

 wards briefly alluded to by him in his " Journal of 

 Researches," p. 448, thus : — 



" A solitary and superficial patch of yellowish limestone, 

 or travertin, which contains numerous impressions of leaves 

 of trees, together with land shells not now existing. It is 

 not improbable that this one small quarry includes the only 

 remaining record of the vegetation of Yan Diemen's Land 

 during one former epoch." 



Strzelecki also notices it in his " Physical Description of 

 N. S. Wales and Y. D. Land," and refers it to Pliocene age. 

 He also gave figures of three fossil plant remains, one of 

 which is the prevailing leaf form in all similar lacustrine 

 deposits. In addition he described and gave figures of two 

 land shells — H. Tasmanicus, G. B. Sowerby, JBidimus Gunnii, 

 G. B. Sowerby — to which I shall refer hereafter. 



Yarious other writers since tbat time have contributed to 

 our knowledge of this interesting deposit, chief among whom 

 was the late Mr. Morton Allport, whose contributions and 

 indefatigable labors in the cause of science have made his 

 name so widely known, and his loss so deeply deplored. To 

 him we owe the knowledge that the fossil bones of Phalan- 

 gista fuliginosa, IIy^sijL)rim7ii, etc., are of later date than the 



