147 



Bridgnorth, and other far inland localities, remains of marine mollusca, of 

 species still existing upon our coasts, was indeed gradual; that it was 

 followed by the formation of a series of brackish and fresh- water lakes ;— 

 and finally by the obliteration of these, by the permanent sea-way, worn 

 through them by the regular water-shed of the lands now forming the 

 banks of the Severn and their relative districts. We have seen that the 

 oolitic drift of the vale, containing elephant and hippopotamus remains, 

 as deposited upon Purton Cliff, near Sharpness, has been abruptly cut 

 through by the Severn, special faciUties for such a proceeding being 

 rendered at that point by the resting of the soft mud, and easily- 

 disintegrated limestone of the lias upon the more resisting masses of Old 

 Red and Silurian. We have seen the so-caUed Northern drift covering 

 the superficial soil at the same locahty, we know, therefore, that it has 

 formed its present course since the last of the great geological changes to 

 which the district in question has been subjected ; and probably so readily 

 traceable, in early times, as regards our human predecessors here, was the 

 ancient strait, fi:om the absence of the plough, or any considerable 

 disturbance of the soil, that Nennius tells us upon the faith of 

 tradition, " Brittones olirn earn (i.e. Britanniam) implentes, a viari usque 

 ad mare judicavenint." 



It is true that he is speaking of two rivers here, of which the Severn is 

 one, and the Thames the other, but the application of the sentence to the 

 Severn in connection with the modern theory, is not the less curious or 

 remarkable. 



Up amongst the bushes which partially cover the lias cliff, as we are 

 occupied chipping the upper band of stone, a sound of wings beating the 

 air comes upon us, and, turning quickly round, we descry a baiTow duck, 

 or shieldi-ake, Tadorna vidpanser, in beautiful plumage, close upon us, 

 steering directly for what we imagine to be a rabbit's hole, partly con- 

 cealed by the disengaged roots of a hawthorn tree. Subsequent enquiries 

 obtain for us the infonnation that a pair or two of these birds have bred 

 here from time immemorial, and that the young are frequently taken by 

 the men who fish for salmon with hand-nets, and that they show an 

 aptitude for domestication, which we think ought to be, but is not, duly 

 encouraged. After remaining for a few days with the ducks of the 

 establishment to whom they may be introduced, they are allowed to 

 escape and rejoin their kindred. From the fact of the bii-d to which we 

 more specially allude, continuing to wheel uneasily about the cliff without 

 alighting we have no doubt that the supposed rabbit-hole was simply its 

 proper abode, and the centre of all its hopes and fears. 



From an isolated patch of Scirpua maritimus, upon the approach of a 

 k2 



