Miss E. Hodgson — On the Fiirness Limestone. 401 



floating ice or icebergs may have assisted the sea in accomplishing 

 so stupendous a result, would form an interesting subject for inquiry. 

 The southern side of the tors has been swept clean. The tail 

 (directed south-south-east) of the western tor has been smoothed and 

 rounded. Both tors, especially on the southern side, have likewise 

 been smoothed and rounded — in many places so independently of the 

 structural arrangement of the rocks, that PI. XVIII. Fig. 9 fur- 

 nishes a correct illustration ; PI. XVIII. Pig. 10, represents the Hey 

 Tors as seen from Ingsdon Hill, looking south-south-west ; {a re- 

 presenting scattered stones). 



, IV. — The Moulded Limestones of Furness. 



By Miss E. Hodgson. 



AT a time when those curious forms often assumed by the upper 

 beds of limestone rocks are thought worth attention, and are 

 brought forward by some geologists as evidences of sea-action, it 

 may not be wholly without interest if I re-introduce a curiously 

 moulded bed of this rock, occurring near Ulverstone. 



In a memoir on the Glacial Drift of Purness (written in 1864, 

 and published in the last number of the " Geologist ") I noticed 

 these stones as having been met with in many places under a thick 

 covering of drift, — in mining, in railway-cuttings, well-sinking, and 

 excavations for building-stones, etc. ; I did not consider them as 

 immediately connected with glaciation, but simply noticed them as 

 examples of the extreme solubility of limestone when remaining 

 long in contact with moisture. 



Not much instruction, however, could at that time be derived from 

 their accidental appearance at various points, often some miles apart ; 

 and it is only within the last few months, owing to greatly-extended 

 quarrying — more methodically carried on, that they have at length 

 been well seen in situ. 



To give some idea of the area over which these moulded stones 

 extend, it will be necessary to describe the position and surface dis- 

 tribution of the Carboniferous Limestone in the district of Purness, 

 or that part of Lancashire which forms the west side of Morecambe 

 Bay. 



This formation constitutes, doubtless, much of the floor of More- 

 cambe Bay ; and on the Purness side of it flanks the Silurians in a 

 long band, from one to five miles broad, and about ten in length, 

 Towards the south, where it is broadest, it is succeeded by the rocks 

 of the Permian series, and is wholly hidden from view at the south 

 end of the Purness promontory. 



The most elevated or thickest part of this range is Birkrigg 

 Common, a ridge rising 446 feet above the sea, and rather less than 

 one mile from the shore. The beds dip shoreward, or south-east, at 

 about an angle of 9°. They are nowhere scarped uito great preci- 

 pices on the shore line ; but when not covered up by beach gravels 

 on the one hand, or Boulder-clay on the other, present fine tabulated 

 slopes to the spray of the sea ; and, despite its defacing action, as 



VOL. IV. — NO. XXXIX, 26 



