122 The Flora of Wiitshire. 
and Pewsey Hills, all commanding the Vale of Pewsey, and crowned 
with ancient earthworks; also Sidbury Hill, Beacon Hill, 690 feet 
high; Mizmaze, Ashley Hill, and numerous others. The earthworks 
of Old Sarum are also very conspicuous, being above 339 feet 
above the level of the sea, presenting from their summit some varied 
and beautiful scenery. It was on the ruins of its walls that Mr. 
Dawson Turner and Mr. Sowerby discovered the rare ‘ Sedum 
sexangulare,” the only locality known for it in England. This dis- 
trict will be found by the botanist remarkably rich in plants. And 
the author is not without hope that its “Flora” may yet be much 
enlarged by further additions. Dr. Southby of Bulford, and James 
Hussey, Esq., claim his especial thanks for the assistance they 
have afforded him. 
%. Soura Western District. 
The south-western district has for its northern boundary the 
Kennet and Avon canal: its eastern being formed partly by the 
Upper Avon, and the railway from Salisbury through Heytesbury, 
Westbury, Warminster, and Trowbridge. The counties of Dorset- 
shire and Somersetshire, respectively, form its southern and western 
boundaries, including an area of about 272 square miles. 
This district contains two small areas of oolitic beds, viz., that to 
the west of Trowbridge, and northwards of Westbury Leigh, and 
the insulated mass of Purbeck and Portland deposits near Chilmark 
and Tisbury in the Vale of Wardour; the Cretaceous series, inclu- 
ding the Upper Green sand tracts,! at Warminster and Horning- 
sham, celebrated for containing fine fossil sponges and other organic 
remains, make up the rest of this district. This district is drained 
by the Salisbury Avon, Nadder, Wily, and their tributary streams. 
From the summit of many of the hills magnificent views are 
obtained. On Cley Hill (900 feet high) the eye ranges south over 
the woods of Longleat, eastward along the boundary of Salisbury 
Plain, and on the west over a cultivated country to the distant 
1 These are here well represented, the whole series of beds of which it is com- 
posed rising abruptly on the north side of the valley, and forming a narrow 
ridge of unequal height. The thickness here is as much as 50 or 60 feet, and 
the upper beds contain Chert. 
