170 



In addition to the above mentioned invertebrate forms, an interesting por- 

 tion of a crustacean was found by Mr. M. J. Scobie in the Upper Ludlow shale, 

 underlying the bone bed, of which the description by Mr. Salter is given below. 



Traces of ichthyic remains, especially the minute teeth of Thelodus parvi- 

 dens, are occasionally found interspersed in the bed No. 10, but never in the same 

 abundance as in No. 9. 



Having thus enumerated the strata of the Hagley Park quarry, and their 

 organic contents, a few remarks must be made on the geological phenomena 

 attending them. 



It has been stated above that the beds here exposed assumed the form 

 of a flattened dome. This protruded dome is about half a mile to the west of 

 the well known dyke of Greenstone, at Bartestree, which cuts through horizontal 

 Btrata of Old Red Sandstone, and runs in an E. N. E. direction towards the 

 southern edge of the protruded Silurian mass of Shucknall Hill (Murchison, Sil. 

 Syst., p. 185). About a mile and a-half further to the S. E. we come to the 

 elevated region of Woolhope, the axis of which runs for more than ten miles 

 still in a S. E. direction. It appears, therefore, that the ejection of the trap- 

 dyke at Bartestree, together with this protrusion of Silurian rocks at Hagley 

 Park, occur exactly on the axial line of the great elevation of Woolhope. 



But though this coincidence of position deserves notice, yet the forces 

 which have caused these minor protrusions have, in fact, acted nearly at right 

 angles to the direction indicated. The Woolhope region, though possessing an 

 axis from N.W. to S.E., is essentially an area and not a line of elevation. Its 

 pressures have been distributed, not in two opposite directions from an axis, 

 but in every direction from a centre. In conformity with this view we find 

 that in its north-western portion it is cut through by the " great Mordiford 

 fault, " running N.E. by E., or nearly at right angles to the major axis, and 

 causing the strata about Dormington and Stoke Edith to assume the same strike. 



Beyond the Woolhope area we find the valley of the river Froome, the 

 Bartestree Dyke, and the protruded Silurian mass of Shucknell Hill, assuming 

 the same east, north-easterly direction. And in the small, dome-like protrusion 

 of Hagley Park, which lies parallel to Bartestree Dyke, and precisely in the 

 axis of Shucknall Hill, we find a further proof of the same movement. 



It appears probable, then, that the pressure caused by the elevation of 

 the central dome of the Woolhope area, acting in every direction, has on the 

 north-west side caused great undulations in the Silurian and Devonian strata, 

 which lie beyond the region of actual elevation. In two instances, those of 

 Hagley Park, and Shucknell Hill, the denudation of the Old Eed Sandstone 

 has exposed to view the subjacent Silurian rocks on the summits of these 

 undulations. Great shattering and dislocation would of course accompany these 

 movements, and in the Bartestree Dyke it is interesting to find one of the grea 1 

 crevices thus formed, and filled with eruption matter derived from the Plutonic 

 region where all these great movements originated. 



