C. CALLAWAY ON THE QUARTZITES OF SHROPSHIRE. 763 



Arenicolites, and portions of one or two more. The burrow is a 

 simple loop, resembling a letter U, 2 inches in length by 1 inch in 

 breadth. I would propose for it the name Arenicolites uriconiensis. 

 If my view of the age of the quartzite is correct, this specimen is, 

 with the exception of the problematical Eozoon, the oldest known 

 fossil. 



B. The Quartzite oe the Stiper Stones. 



The physical characters of this rock have been so well described 

 by Murchison (' Siluria,' cap. iii.), that it will be unnecessary to 

 make additional observations. I have but to add a suggestion on its 

 geological age. By the author of ' Siluria,' it is placed on the 

 horizon of the Lingula Flags, on the ground that it is below the 

 Llandeilo, and contains worm-burrows and fragments of a Lingulid, 

 which, it is candidly stated, does not resemble Lingulella Davisii. 

 Geologists of the present day will hardly be disposed to accept such 

 evidence as conclusive. The shales overlying the quartz-rock contain 

 Illcenus jperovalis, Cdlymene parvifrons, JEglina, Placoparia, and 

 other Arenig forms. There can therefore be little doubt that the 

 quartzite is of Arenig age, and, consequently, quite distinct from the 

 quartzite of the Wrekin area. The two rocks can generally be 

 distinguished from each other even in hand specimens ; and, when 

 they are conglomeratic, the pebbles of the Arenig quartzite mainly 

 consist of quartz, while the included fragments of the Wrekin quartz- 

 rock are felsitic. 



Note. — Since writing the chief part of this paper, I have detected the 

 Shineton Shales in force at the base of the escarpment of the Stiper 

 Stones, and dipping under the Arenig series in the same direction as 

 the rocks of that formation — that is, west-north-west. The plane of 

 separation appeared to me on a hasty inspection to be a fault. 

 This supplies additional proof of the Tremadoc age of the Shineton 

 Shales, and of the separation of the underlying Wrekin quartzites 

 from the overlying quartzites of the Stiper Stones. 



Discussion. 



Dr. Gwyn Jepereys doubted whether the boring had been that 

 of an Annelid, especially as the rock was not calcareous. 



Mr. Etheridge expressed his agreement with the position assigned 

 to the Hollybush Sandstone in the area described by the author, and 

 thought that the results of the paper were of great interest and value. 



Dr. Hicks thought that the burrow was very like one in the Stiper 

 Stones and in similar sandstones in Scotland, and that the quartzites 

 were hardly so old as the author supposed ; but he agreed with the 

 author as to the probably Precambrian age of the volcanic group. 



Mr. Callaway responded, giving some explanation of the apparent 

 difficulties in the sections, which were to be explained by faults. 

 In reply to Dr. Hicks, he held that the stratigraphical position of 

 the quartzite was far more decisive than lithological resemblance or 

 the similarity of Annelid-burrows. 



