168 



beds, by Messrs. Etheridge and Lesquereux, is correct, and 

 that this may be looked upon as that of the Lingula Flags or 

 Menevian beds of Great Britain, and the Potsdam Sandstone 

 of North America. 



associated with the Trilobitic remains just described, are 

 those of small discoidal, or planorbicular Univalves. (PI. 2, 

 Fig. 13 and 14.) The specimens are mere casts, but they present 

 all the appearance of the genus Ophileta, Vanuxem, one 

 (Fig. 13) more especially than the other. As a rule, the side 

 of the shell visible in the present specimens is the upper or 

 concave, showing the sunk spire. The whorls are truncate 

 and biangular exteriorly. Ophileta, which is chiefly an 

 American genus, occurs commonly in the Quebec Group beds, 

 somewhat higher in the series than the Potsdam Sandstone. 

 On the whole, it strongly corroborates the deduction drawn 

 from the Trilobites, as to the stratigraphical position of the 

 beds in question. There are also the internal casts of a very 

 peculiar bivalve. This I am at present unable to refer to any 

 genus, and must defer an opinion on it to some future occasion. 

 In the meantime it is simply figured. (PI. 2, Fig. 15.) 



2. BRACHIOPODA FROM THE CONGLOMERATE OF TABLE CAPE. 



(Plate 2.) 



Mr. T. Stephens has described the geological features of 

 portions of the North Coast of Tasmania in a very interesting 

 paper, " Remarks on the Geological Structure of Part of the 

 North Coast of Tasmania," etc. According to his observations, 

 there exist along the line of coast, westward from the River 

 Tamar, beds of conglomerate in a series which is possibly of 

 Silurian age.* Between Port Sorell and Table Cape, and 

 above the former, he describes horizontally bedded con- 

 glomerates and breccias, unconformably underlying the 

 Tertiary freestone of the Cape, said by Prof. McCoy to be 

 of Miocene age. The conglomerate in question consists of 

 rolled pebbles, and angular fragments of the primary rocks of 

 the neighbourhood, and the Plutonic rocks associated with 

 them. Mr. Stephen& adds, " It contains boulders derived from 

 rocks which are not older than the Lower Carboniferous or 

 Devonian period."t 



Mr. R. M. Johnston has likewise described X t^is deposit, 

 forming, as he states, the floor of the Tertiary beds at the 

 locality in question, and containing here and there highly 

 fossiliferous blocks, in one of which Brachiopoda were 

 abundant. Mr. Johnston believes the Table Cape conglomerate 

 to be identical with that of the Dial Range, which is considered 

 by Mr. Gould to be of Silurian age. The remarks of the 



* Papers and Proc. 1869, p. 17. t Ibid, p. 18. 



t Further Notes on the Tertiary Marine Beds at Table Cape. Papers and Proc. 



R. S. Tas. for 1876, p.p. 79— 90f. 



