BAISED BEAOHES. 421 



bedding with intervals of loose sand ; a few shells {Patella and 

 Buccinum) have been found in it ; and recently, in its upper part, 

 ten feet below the surface of the present soil, were discovered 

 bones and teeth of the elephant, rhinocerous, bear, horse, and 

 deer ; the caudal vertebrae of the whale, and the lower valve of 

 a large oyster." By this extract the continuation of the gravel 

 down to the then sea-beach appears to be confirmed."''^ 



Having thus described the nature of the beds, the two points 

 of especial interest for our further enquiry are : The origin of 

 the patches of the diluvial gravel and clay, on the surface of the 

 Hoe ; and of the loam and pebbles which fill the expanded 

 joints of the limestone. 



The nature of the materials of which the pebbles are 

 mainly composed, strongly indicate the locality from whence they 

 were derived, and point to the geological district north of Ply- 

 mouth and west of the granite boss of Dartmoor. In particular 

 the quartz pebbles are in their structure precisely similar to the 

 large boulders of quartz known as the Whitakers, which abound 

 near Uplands in the parish of Tamerton Foliot, about 5 miles 

 north of Plymouth, On the 16th of August, 1887, I gave a day 

 to the geological survey of this district ; Mrs. Fox courteously 

 sent her gardener with me to point oat the main sites of the 

 Whitakers. The largest boulder met with was in a plantation 

 south of the farm-yard, it is egg-shaped, measures about 10 feet 

 by 5, and lies half -buried in a mass of smaller boulders and clay. 

 Further south, in the roads near Loosely, many indications of 

 similar deposits may be seen. Mr. Pengelly, F.E.S., in his 

 description of the Whitakers, says — "That the blocks have 

 travelled a considerable distance cannot be doubted .... and some 

 of the blocks instead of lying at once on the shillet, were 

 lodged in a heterogenous accumulation of clay and stones, includ- 

 ing Whitakers from the size of an ordinary apple to that of 

 a common cocoa-nut."f Other pebbles on the Hoe were similar 

 in structure to the fine-grained quartzite exposed in Cann Quarry, 

 and the most perfectly rounded pebbles were composed of hard 

 black hornblende, derived from the border of the Dartmoor 



*" Eeport of the British Association," 1841, Abs. of Trans., p. 62. 

 t "Trans, of Devon Assoc," Vol. 12, \y. 311. 



