500 C. Lajnvorth — On British Graptolites. 



We know that deposition and denudation are inseparable cor- 

 relatives, and that the amount of destruction done upon the older 

 rocks is measured by the sedimentary deposits derived from their 

 materials ; but the recognition of these facts gains more than ordi- 

 nary significance when we come to consider of how much of those 

 hidden mineral treasures we prize so highly, and the extension of 

 which we seek so earnestly, as the means of perpetuating our 

 national prosperity, we have been deprived by the former agency. 



Along the line of ground marked by the barrier before referred to 

 as separating the marine Devonians from the fresh-water Old Eed 

 Sandstones of this district, Palaeozoic rocks are described as crumpled 

 and contorted for a breadth of many miles, and along a length of 

 800 miles, tilting and turning the Coal Measures back upon them- 

 selves, squeezing and folding them, so that the crown of the anti- 

 clinal is sometimes four or five miles above the level of the reversed 

 synclinal arch to which the bottom Coal Measures descend in Belgium. 

 One of these anticlinals presents itself at Linley, on a small scale 

 it is true, but bearing the unmistakable impress of the forces to 

 which it is due, and betraying to the experienced eye the direction 

 in which denudation has done its work. All such tilted beds must 

 have had broken edges somewhere, and those edges once exposed 

 to the waves, the work of denudation would commence along the 

 line of fracture.^ 



Y. — Notes on the British Gkaptolites and their Allies. 



By Chas. Lapworth, F.G.S. 



1. — On an improved Classification of the Ehabdophora. 



PART I. 



IN the following communication I intend to give a very brief outline 

 of some of the chief results of my investigations among British 

 Graptolites in those departments of inquiry which are more especially 

 connected with considerations of classification. I shall content myself 

 with offering a concise statement of the main conclusions at which I 

 have arrived, reserving all detail to the future, when I hoj)e to adduce 

 decisive evidence in support of the views here advanced. The special 

 subjects to be noticed in this place are — ^the development, structure, 

 classification, and geological distribution of that section of the Ehabdo- 

 phora in which the complete polypary can be proved to be composed 

 of one or more polyparies essentially similar to that in the unilateral 

 and uniserial forms to which the name Graptolites (Graptolithus) is 

 commonly applied. Those Ehabdophora supposed to be similar in 

 structure to the genus Eetiolites will be considered in conjunction, 

 but no pretension is made to anything like the same certainty in this 

 section. In an outline paper like the present, which may be looked 

 upon simply as a registration of new discoveries and opinions, it 

 becomes possible to dispense with that constant reference to the 

 collateral labours of other investigators which strict justice demands 



' Read before a Field-meeting of tlie Dudley Geological Society, held at Liuley 

 near Bridgnorth, on 17th September, 1873. 



