W. A. E. Ussher— Subdivisions of the Trias. 165 



4. — Bed Variegated Marls, slightly calcareous, loamy in the 

 lower portion, and containing impersistent beds of sandstone near 

 the base. 



5. — Eed sandstones and beds of rock-sand, locally brecciated. 

 Breccia, angular fragments of grit and quartz, in rock-sand. Brec- 

 cia, hard and thick bedded, fragments of locally derived rocks. 

 Breccia, gravelly, large grit pebbles in sand, with intercalated beds 

 of rock-sand. Breccio-conglomerate, pebbles and subangular frag- 

 ments of grit, quartz, and locally limestone. Breccia of shale 

 fragments in red loam and loamy clay. Dark red clay, mottled grey, 

 of very local occurrence. 



1. — The Upper Marls. 



The above name is applicable to these beds, between Watchet and 

 the south coast of Devon, only near the line of outcrop of the under- 

 lying sandstones, as in the large tract of country in Somersetshire, 

 north and south of Taunton, over which the Trias is exclusively 

 represented by Marls, it is very doubtful whether the west Somerset 

 and Devon divisions underlie them. On the coasts of Devon and 

 "West Somerset, the Marls are in places intersected with gypseous 

 veins ; but in the intervening country they are not observable, pro- 

 bably owing to the absence of extensive sections. 



The lower beds are loamy, sometimes almost passing into rock- 

 sand. Near Sampford Arundel (near Wellington), and at Sidmouth, 

 a bed or two of sandstone is observable, showing a transition to the 

 underlying sandstones. 



2. — TJie Upper Sandstones. 



So called here to distinguish them from the sandstones of No. 5 

 (the lowest division). On the coast of Devon they consist of red 

 sandstones, with pockets of red clay occasionally, and corrugated 

 calcareous nodular bands. About 50 feet from their base are found 

 the celebrated conglomeratic beds of Otterton Point, memorable as 

 the locality where Mr. Whitaker's Hyperodapedon was discovered. 



This division is persistent over the whole area, with one exception, 

 south of Watchet, where it is faulted out, showing itself however in 

 one or two places along the line of fault. 



Inland, the Upper Sandstones exhibit great variety of colour and 

 composition. In some places they resemble greensand, and have 

 even been mistaken for it on Woodberry Common, north of Exmouth. 

 Between Bishop's Lydeard and Crowcombe Heathfield, south of 

 Watchet, the sandstones are exceedingly calcareous, and contain 

 uneven beds of bluish rock, resembling a marlstone ; these have been 

 carefully observed by my colleague, Mr. J. H. Blake. The calcareous 

 sandstones of this district are burnt for lime. The Otterton Point 

 beds prepare us for the next and underlying member, the Pebble beds 

 and Conglomerate. 



3. — The Pebble Beds and Conglomerates. 



This division is the thinnest in the series, seldom exceeding 

 100 feet -in the Conglomerates, and 60 feet in the Pebble beds ; con- 



