408 Geological Society. 



laminated clay ; but it appears to have been in some places tran- 

 quilly accumulated, as specimens of Nucula Cobboldice, Tellina obliqua, 

 and Mya arenaria, occur with the valves imited, and not worn by 

 attrition. In the same beds, however, are procured rolled fish- 

 bones, and remains of the elephant, rhinoceros, horse, and deer. 

 Capt, Alexander found at the base of the cliff, in a bed about 6 

 inches thick and rich in marine shells, the tooth of a horse within a 

 large Fusus striatus. That gentleman also possesses a tooth of a 

 mastodon, washed out of the cliffs between Dunwich and Size- 

 well. 



In tracing the Norwich crag from Easter Bavant northward to- 

 wards Kessingland, Mr. Lyell found in it layers of flinty shingle ; 

 and he consequently refers to this formation, those strata of sand 

 and shingle, on the coast, which resemble the sandy portions of 

 the plastic clay of the London and Hampshire basins. 



In some of the inland pits of Norwich crag near Southwold, the 

 author found mammiferous remains associated with a variety of 

 Cyrejia trigonalis, a shell common in the freshwater deposit of Grays, 

 and elsewhere. 



In the neighbourhood of Norwich the deposit forms patches of 

 very variable thickness, resting upon chalk, and covered by a dense 

 bed of gravel. It is best displayed at Bramerton, Whitlingham, 

 Thorpe, and Postwick, and consists of sand, loam, and gravel, en- 

 closing marine, land, and freshwater shells, with ichthyolites and 

 bones of mammalia ; and Mr. Lyell says, it was evidently accumulated 

 near the mouth of a river. The late Mr. "Woodward describes the 

 chalk of Postwick as having been drilled by marine animals before 

 the deposition of the crag ; and the Rev. Mr. Clowes found in a per- 

 foration in the chalk at Whitlingham the shell of a Pholas crispatus, 

 the remainder of the perforation being filled with crag. Among 

 other proofs that the strata were gradually deposited, the author 

 mentioned Capt. Alexander's discovery of an elephant's tusk, with 

 many serpulse attached to it ; and he infers from this fossil, that the 

 remains of the mammalia were really washed into the sea of the 

 Norwich crag, and were not subsequently introduced by diluvial 

 action, as some observers have suspected. The freshwater shells, 

 although most diligently searched for, are less abundant than 

 marine, and the terrestrial are still more rare ; but Mr. Wigham has 

 found in one bed at Thorpe, a great predominance of fluviatile tes- 

 tacea. In the same pits he obtained a mastodon's tooth at the bottom 

 of the deposit, near the chalk, associated with pectens and other 

 marine shells. In the beds at Postwick, he also discovered, in 

 1835, part of the left side of the upper jaw of a mastodon, con- 

 taining the second true molar. This fragment Mr. Owen has been 

 able to identify with the Mastodon longirostris of Eppelsheim. In 

 the same bed, Mr. Wigham also obtained the teeth and jaw of a 

 field-mouse, larger than those of the common species ; likewise 

 remains of birds, and several species of fishes. The horns of stags, 

 bones and teeth of the horse, pig, elephant, and other quadrupeds, 

 have been obtained at Postwick, Thorpe, Bramerton, &c., near 



