440 Mr. Austen on the 



angular and flattened, rather than rounded, forms of the materials, their arrangement, and those direc- 

 tions of the banks of sand (which is such as may be observed in estuaries), which were caused by the 

 currents produced in the lake by streams discharging at the same points at which they now enter the 

 valley. The estuary of the Teign, but for artificial embankments and a wear, would even at present ex- 

 tend nearly as far as Teign Bridge, for the foundations of the present structure are on a level with the 

 sea at Teignmouth. From Teign Bridge to the upper part of the valley near Bovey, there is a rise of just 

 eighty feet ; so that before that elevation took place, of which there are such numerous proofs, the whole 

 of this basin must have been placed beneath the level of the sea. 



The bones of the wild boar, the ox, and the red deer are found in the superficial sands of the Bovey 

 valley, and beds of peat have often been discovered beneath the " head " in openings made in search for 

 clay-beds. The bones of this lacustrine accumulation are black, with a smooth polished surface, resem- 

 bling those which are now found in the beds of rivers or ponds, and are very unlike remains from 

 breccias ^nd caves, which are either white or slightly stained with red, and are corroded on the surface, 

 as if they had been long exposed to the atmosphere. 



§ 5. Raised estuaries. — The general features of some of the valleys as they ap- 

 proach the sea, suggest that they were formerly estuaries, though at present only 

 very inconsiderable streams of water flow through them ; thus the broad level de- 

 posits of the valley of the Axe could hardly have been accumulated by any shiftings 

 and expansions of the present river. Next to the eastward, the valley of the Otter 

 presents for several miles inland a flat extent of meadow bounded by vertical cliff's 

 ( § 1 . p. 434) . In some places, as from Datton Mill towards Newton, the stream flows 

 at the base of cliffs consisting of compact beds of new red sandstone ; through 

 the greater part of its course, however, it does not approach them, but occupies 

 a deep channel along the central line of the valley ; these vertical cliffs therefore 

 cannot possibly have been produced by any causes in present operation, and 

 clearly indicate the extent of the former estuary. On the eastern side of the 

 valley, below Datton Mill, is a remarkably good section, presenting three feet of 

 silt, resting on a considerable thickness of sea-sand, the whole being placed on the 

 coarse gravel of the district. 



In the upper part of the estuary of the Exe, from Topsham to Alphington, and particularly along the 

 western side, is a flat expanse of land, high above the present water level, but which must have been 

 accumulated under salt or brackish water ; the beds abounding with existing British species of Mactra, 

 Tellina, Cardium, &c. These shells are found in the nursery-grounds of Messrs. Pince, as high up the 

 valley as north of the main road leading from Alphington into Exeter. The great width of the body of 

 water which formerly occupied this valley, is easily observed in still higher parts of its course. 



The tract at the mouth of the Exe, known as the Warren, consists, on the sea side, of lines of sand- 

 hills or dunes of some elevation, resting on a broad bank of sand and shingle of purely marine origin. 

 This bank belongs to the time when the valley had a lower level, or was constantly submerged, and when 

 the sea reached the base of the cliffs on the western side of the mouth of the river, and produced the 

 range of cliff's running inland from Warren Point. As at the mouth of the Taw, where we have a like 

 order of things on a rather larger scale, there is no real line of separation between the blown-sands and 

 the subjacent coarse beds, which contain marine shells, so, at the mouth of the Exe, we have a passage 

 upwards from beds purely marine into others of a fluvio-marine character, graduating into such as swarm 



