248 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Mar. 5, 



7. Alternating reddish and grey slates and sandstones succeed. 



8. And these are overlaid by red sandstones, which form a band 

 three miles broad, extending from the Portway about three and a half 

 miles to the westward, chiefly vertical, or with a westerly high dip ; 

 they include thick bands of conglomerate ; the principal band is 120 

 feet thick*. 



It is only in the grey sandstones, No. 3, that the fossils were found, 

 and these sandstones are so interstratified with the red shales, alter- 

 nating with them and dipping in the same direction, that it is im- 

 possible to regard them as anything but a part of the Longmynd 

 series, and rather low down in it. 



The olive shales, Nos. 1 and 2, were searched vainly for any fossils, 

 and the greater portion of the next series. No. 3, which forms the 

 first considerable ridge, is of too fine and homogeneous a texture to 

 promise much. At the upper part, however, the beds are coarser 

 and more flag-like, and show considerable variations of surface. 



Organic Remains^. — On the beds last mentioned, at the Carding 

 Mill, Church Stretton Brook, are numerous double impressions, not 

 a line long, but covering in quantities the surface of the slabs (PI. IV. 

 fig. 1). They are elongated in one direction, and appear nearly 

 always parallel to each other, — a circumstance that at first suggests 

 their being merely mechanical marks, such as minute ripples or 

 ridges. But, when closely examined, they are found to be regular 

 in size, constantly double, and distinctly of two kinds, viz. one set 

 consisting of strongly impressed holes, as if recently made, — and. 

 others faint, as if subsequently effaced. I do not know anything to 

 which these markings can be properly referred, unless it be the holes 

 of marine worms, something like the Lob-worm of our own coasts. 

 It will be remembered that Mr. BinneyJ first described such mark- 

 ings as the burrows of Annelides : they occurred in the flaggy sand- 

 stones of the lower division of the Lancashire coal-field ; and he had 

 ample reason for believing his conjecture to be a correct one, by 

 finding the holes connected by a loop-like tube beneath the surface. 



"We may call ours, from analogy with these, 



Arenicola didyma. pi. IV. fig. \ a, \ b. 



A. fodinis didymisy minutis, approximatis, ellipticis, scepissimh 

 parallelis. 



The most remarkable point, indeed, about these markings, whether 

 the deep, or the obliterated ones, is their parallelism. They never 

 deviate more than a degree or two from it ; and, that this is not due 

 to lateral pressure, is clear from the fact that the position of the 



* This conglomerate, recently cut through by the new road to Ratlinghope, is 

 of a very soft texture, easily worn away, and therefore not conspicuous except 

 in brook- or road- sections. Quartz-rock is its chief constituent ; syenite is very 

 rare. 



t The fossils described in this paper are in the Museum of the Geological 

 Survey. 



X Mem. Lit. Phil. Soc. Manchester, 2nd Ser. vol. x. p. 191. pi. I. fig- 2. 



