1852.] PRESTWICH ON THE HOLMFIRTH FLOOD. 225 



during the Secondary and Devonian periods, what may not have been 

 the modifications of the Articulate type during a period probably 

 more remote from the Secondary period than this is from the present 

 time ! In all probability no living form of animal bears such a re- 

 semblance to that which the Potsdam foot-prints indicate, as to afford 

 an exact illustration of the shape and number of the instruments and 

 of the mode of locomotion of the Silurian Protichnites. 



These most precious evidences of animal life, locomotive on land, of 

 the oldest known sedimentary and unmetamorphosed deposits on this 

 planet, have been, I am well aware, far too inadequately described in 

 the paper which I have had the honour to submit to the Society. 

 They offer characters which require more time for their due scrutiny 

 and greater acumen and powers of interpretation than have hitherto 

 been bestowed upon them. The symbols themselves are distinct 

 enough. Old Nature speaks as plainly as she can do by them ; and 

 if we do not fully thereby read her meaning, the fault is in our 

 powers of interpretation. In the present attempt I can, however, 

 truly aver, that I have bestowed upon it all the leisure at my com- 

 mand, and have applied my best abilities in the endeavour to fulfil 

 my obligations to their discoverer, and to satisfy the generally ex- 

 pressed wishes of the Society. 



April 7, 1852. 



Lieut. Julius Roberts, R.M.A., and the Hon. D. F. Fortescue 

 were elected Fellows. 



The following communications were read : — 



1. On some of the Effects of the Holmfirth Flood., 

 By Joseph Prestwich, Jun., Esq., F.G.S. 



The broad tract of hilly country, which stretches north and south on 

 the borders of Lancashire and Yorkshire, rises, in some places between 

 Manchester and Huddersfield, to the height of nearly 2000 feet. 

 The central ridge is here composed of the Millstone Grit Series, the ele- 

 vated surfaces of wbich form extensive barren moors, and from which, 

 owing to their lithological character and the large fall of rain, the sur- 

 face-drainage is very considerable. On its eastern slope, the water is 

 carried off by numerous small streams, falling into the various tribu- 

 taries of the Humber. Their usual course is through narrow and 

 picturesque valleys, which penetrate deep into the hills ; amongst 

 them is that of the Holme, which commences in the central range of 

 hills, winds for nine miles east and north, and then joins the valley 

 of the Colne at Huddersfield : it is well-wooded, and the scenery is 

 generally bold and fine. At a short distance from the top of the 

 valley, the Holme is joined by the Digley streamlet ; the latter, how- 

 ever, being apparently the main stream, and draining, according to 



