VI] REDWOOD AND MAMMOTH TREES 101 



and by beds of tlie same age in other countries. 

 A small cone has recently been described from 

 strata near Boulogne belonging to the latest phase 

 of the Jurassic period, which presents a strong 

 resemblance in shape and size and in the form of the 

 cone-scales to those of the recent species. This speci- 

 men, though not conclusive, is the most satisfactory 

 indication of a Jurassic Sequoia so far discovered. 

 From Lower Jurassic rocks in Madagascar similar 

 cones have been recorded in association with foliage- 

 shoots like those of Sequoia gigantea, but here too 

 the evidence is not beyond suspicion. In plant- 

 bearing strata of Wealden age, such as are exposed 

 in the cliff near Hastings and in deposits of the same 

 age in North Germany, Portugal, and elsewhere, 

 twigs and cones have been found Avhich may be 

 those of trees nearly allied to the genus Sequoia. 



It is, however, in the sedimentary rocks of 

 Cretaceous age, rather higher in the series than 

 those in the Hastings cliffs, and in the succeeding 

 Tertiary rocks, that undoubted Sequoias are met 

 with in abundance. At Bovey Tracey in Devonshire 

 there is a basin-shaped depression in the granitic rocks 

 of Dartmoor filled with clay, gravel and sand — the 

 flood-deposits of a Tertiary lake containing waifs and 

 strays of the vegetation on the surrounding hills. 

 Among the commonest plants is one to which the 

 late Oswald Heer gave the name Sequoia CouUsiae, 



