786 



on the east side of the river. Braunton Burrows is a district of 

 sand-hills, about four or five miles in length, skirting the coast from 

 the north bank of the estuary to a raised beach, which forms part of 

 the northern boundary of Barnstaple Bay. They extend inland from 

 two miles to two miles and a half, when they gradually merge into the 

 flat marsh which occupies the remainder of the valley. The sand- 

 hills vary from ten to thirty or forty feet in height, and are continu- 

 ally receiving fresh accumulations of sand from the sea, which renders 

 Ihem, immediately on the coast, almost devoid of vegetation. Ammo- 

 phila arundinacea is here almost the only plant that survives the 

 repeated interments ; and by the aid of its fast-growing stolons, which 

 readily penetrate the loose sand, it easily re-establishes itself on the 

 surface, even when buried at a considerable depth. Vegetation gra- 

 dually improves as we recede from the coast, and is richest on the 

 inland boundary of the sand-hills, where they are intersected by seve- 

 ral moist, flat valleys. These are the habitats of some of the most 

 interesting plants of the district ; amongst which, Scirpus Holoschoe- 

 nus, Bartsia viscosa, and Teucrium Scordium stand foremost in point 

 of rarity. The marsh-land to the east of the sand-hills is partially 

 under cultivation ; but the greater part is unenclosed, and covered 

 with a maritime vegetation. The most prevalent plants here are Jun- 

 cus maritimus and J. acutus. The latter attains a great height, many 

 tufts being considerably taller than a man. 



Northam Burrows consist of a salt-marsh, about 800 acres in ex- 

 tent, bounded on the west by the sea, and on the north and east by a 

 narrow belt of sand-hills, which separates it from the estuary. Ex- 

 tending from the cliffs on the south side of the bay to the mouth of 

 the river, is a high bank of boulders, known as Northam Pebble-ridge, 

 which protects the marsh from the inroads of the sea. 



Instow Burrows are situated on the east bank of the Torridge, at its 

 confluence with the Taw. They are less extensive than either 

 Northam or Braunton Burrows, and consist of a small range of sand- 

 hills skirting the rivers, which, further inland, give place to an unre- 

 claimed marsh, similar to that on the opposite shore. 



The higher land to the south of the alluvial valley is situated at the 

 northern extremity of the barren carboniferous beds of Devon. They 

 consist of highly contorted beds of gritstone and shale, thrown into 

 long, rounded hills, running east and west, the anticlinal areas of the 

 strata being in that direction. 



The barren carboniferous strata are bounded on the north by beds 

 of a dark gray limestone, interstratified with a compact slaty rock, 



