316 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [June 1, 



Returning to Barrow Straits. The ballast from Leopold's Island, 

 before quoted, yielded — 



Favosites polymorpba. Abundant. 



Gothland ica. 



Fenestella, sp. Probably the same as above. 



Strophomena, sp. Same as No. 13. 



Rhynconella Phoca. As above. 



sublepida, De Fern. The ribs in the middle of the shell 



are not quite of the same size as in the Ural specimens, and 



seem more prominent. 

 47. , sp. Simple plaits. Distinct from No. 20. 



The existence of this great formation of Upper Silurian limestone 

 along the shores of Prince Regent's Inlet is rendered all but certain 

 from the notes furnished by Prof. Jameson and Mr. Konig in the Ap- 

 pendices to Capt. Parry's Voyage. From their accounts, the coasts 

 are occupied by a transition limestone of an ash-grey or yellowish 

 and grey colour, often foetid, and sometimes crystalline or compact. 

 It is described as filled with zoophytes and shells, and in certain 

 parts, as noticed by Mr. Konig, quite made up of the detritus of 

 Encrinites, the fragments of which are so comminuted that it might 

 readily be mistaken for a granular limestone. He also found in it 

 the chain-coral. 



Prof. Jameson gives a list of organic remains from Port Bowen, 

 which, by modernizing the nomenclature of the fossils, would agree 

 well with those from the north shore of Barrow Straits, and indeed 

 he has himself identified them. And he mentions that this same 

 rock extends eastward to Cape York, Admiralty Inlet, and even 

 occurs at Possession Bay, while in a southerly direction it was found 

 as far as the Regent's Inlet was explored. We have seen that a 

 similar limestone occurs at Cape Walker, Russell Island ; and from 

 the general low character of the shores that stretch to the west (ex- 

 plored lately by Capt. Ommanney), it is probably continued along 

 them. 



The north-eastern shores of Lancaster Sound are composed, at 

 least in part, of igneous and crystalline rocks ; but from the com- 

 mencement of the table land at Powell's Inlet all along the coast 

 to the Wellington Channel, a uniform appearance of the shore (the 

 cliffs appearing like fortifications) indicates the presence of the same 

 tabular strata of limestone. Dr. Sutherland, who is well acquainted 

 with the appearance of the limestone cliffs, and who had the advan- 

 tage of communicating with the different exploring parties, is without 

 doubt of its continuity along this coast. 



Again : the limestone of Melville Island, according to Mr. Konig, 

 contains Favosites and TerebratuIcB. Dr. Conybeare adds to them 

 Cateniporce and CaryophylUce ; and this is just the aspect which the 

 fossils of the limestone we have described would present on a cursory 

 examination. In Melville Island, however, it is connected with a 

 sandstone and coal formation, with a carboniferous flora ; and as this 

 sandstone contains Trilobites, Encrinites, and Aviculce, we may hesi- 



