INTEODUCTION. 



TOPOGRAPHY. 



Plymouth is situated in latitude 50° 22', on the west hank of the estuary 

 of the river Plym, close to its junction with the estuary of the river 

 Tamar ; and at about four miles north of the open English Channel. 

 Immediately to the south of the town the waters of both the Plym and 

 the Tamar are discharged into Plymouth Sound. 



The land falling under a radius of twelve miles from Plymouth as a 

 centre forms the area of this Flora. Thus the tract is made up of a part 

 of south-west Devon and a smaller portion of south-east Cornwall. Its 

 extent, on a rough calculation, is about 170,000 acres. Devon contains 

 1,657,180 acres {Agricultural Returns, 1871) ; thus the extent of the 

 area of the Flora compared with that of the whole of Devon is nearly in 

 the proportion of one to nine. 



A reference to the map Anil show that the greater portion of the land 

 lies north of Plymouth ; that in the opposite direction stretching to a 

 comparatively inconsiderable extent, and being much broken into by the 

 influx of large bodies of salt water. 



Elevation and Surface Features. — The face of the country is 

 extremely diversified ; hills and dales appear in quick succession over the 

 greater part of it. In a north and north-easterly direction from the town 

 of Plymouth hill after hill rises higher and higher on to Dartmoor, where 

 the peaks become almost mountainous in character ; Shell Top and Pen 

 Beacon, near the village of CoruAvood, respectively attaining 1,600 and 

 1,740 feet, and the Western Beacon and Butterton Hill, both near Ivy- 

 bridge, 1,203 and 1,130 feet. West of Dartmoor a high table-land inter- 

 venes between the rivers Tavy and Tamar, 705 feet high at Morwell Down, 

 between Tavistock and New Bridge, but of less elevation towards the 

 south. This is succeeded on the right bank of the Tamar by a tract very 

 simUar to Dartmoor in character ; its highest point, Kit Hill, 1,067 feet, 

 lies just beyond the area. Thence southwards to the coast the surface 

 has much the aspect of the country between Plymouth and Dartmoor. 



b 



