THE DERWENT DISTRICT. 207 



Hygrophilous plants are to be met with, of which the following 

 are the most noteworthy : 



Nyjiiphcea alba 

 Ranunculus Lingua 

 Shim latifoliuin 

 Cicuta virosa 

 CE nan the crocata 

 Hydrocharis Morsus-rance 

 Sagiltaria sagittifolia 



Bictonuis umbellatus 



Potamogetofi flabellatus 

 ,, graviineus 



,, lucens 



Lenifia polyrrhiza 



Acorus Calavuis 



Rumex Hydrolapathum. 



The Howardian tract is separated on the north-west from the 

 range of the calcareous hills over Ampleforth and Oswaldkirk 

 by the hollow along which runs the Thirsk and Malton Railway. 

 The southern of its two terraces, that which is composed of 

 sandstone, is during part of its course the watershed between 

 Foss and Dervvent. Beginning at the north-western extremity, 

 we have the park and hall of Newburgh upon its slope towards 

 the railway, and the moors of Yearsley and Oulston upon the 

 summit of the ridge, which, at this point, is nearly 600 feet in 

 elevation. A few miles further east are the park of Wiganthorp, 

 and the moor of Scackleton, below which rises a stream which 

 flows on the south side of the ridge past the villages of Bulmer 

 and Foston-le-Clay to the Derwent. Mowthorpe Dale is a small 

 wooded glen where a branch of this stream penetrates the ridge. 

 Then comes the village of Terrington and the woods and park 

 and mansion of Castle Howard. The ridge at this point is not 

 more than 300 feet in elevation, and it declines still more past 

 Whitwell, Welburn and Crambeck, in the direction of the 

 Derwent. 



The northern of the two terraces, that which is composed of 

 calcareous materials, runs parallel with the other, but is not con- 

 tinued so far westward. On the south it has a steep escarpment, 

 which in many places is covered with wood, but on the north its 

 slope towards the Vale of Pickering is more gradual. At Gilling 

 the sylvan nab which forms the termination of the ridge in a 

 western direction, stands out boldly against the hollow along 

 which the railway runs. At Hovingham and Slingsby two streams 



Jan- i8?9. 



