A HISTORY OF SUFFOLK The newer division, termed the Butleyan, and known to all col- lectors in the well-known pit near the Butley Oyster Inn, is characterized as the zone of Cardium grosnlandicum, and is recognized by Mr. Harmer in the cliff at Bawdsey, where the Red Crag overlies the London Clay ; also in pits at Alderton, Hollesley, Boyton, Chillesford, Sudbourne and Iken. The characteristic fossils of the Red Crag are Neptiwea {T'rophon) antiqua, N. contraria. Purpura lapillus, Natica (several species), Cassidaria bicatenata, Nassa (several species), T'urritella incrassata, Tellina obliqua, T'. prcetenuis, Mactra ovalis, M. constricta, Cardium angustatum, Pectunculus glycimeris, Scrobicularia plana (in upper beds), Pecten opercularis, Mytilus, My a, etc. The basement bed, to which reference has previously been made, is of considerable interest, as it contains many bones as well as other fossils, and masses of hardened clay or septaria from the London Clay, all rolled and phosphatized, and known commercially as ' coprolites.' The bed is from 6 inches to about 3 feet thick, and the phosphatic nodules or coprolites, which are occasionally dispersed through the formation, have been extensively dug since the middle of last century. In 1847 about 500 tons were raised, in 1854 12,000 tons, in 1889 5,000 tons, since which date the trade has gradually declined, and was finally abandoned owing to the introduction of foreign phosphates. Attention was first directed to the nodules by the Rev. J. S. Henslow,' for many years rector of Hitcham, who in 1842 observed the curious nodules in the Red Crag at Felixstow, and afterwards found some which were clearly coprolites. They have been found to yield from 44 to 60 per cent, of phosphate of lime ; and have been worked at Walton, Trimley, Falkenham, Foxhall, Bawdsey, Ramsholt, Shottis- ham, Sutton and Boyton.'^ Many vertebrate remains have been obtained from the coprolite bed, and notable collections have been made by the Rev. H. Canham of Waldringfield, Messrs. Whincopp and J. Baker of Woodbridge, and Mr. E. Cavell of Saxmundham. Among the remains there occur the ribs and ear-bones (cetotolites) of whales, bones and teeth of mastodon, rhinoceros, tapir, hyaena, etc. NORWICH CRAG To the north of Aldeburgh the place of the Red Crag appears to be occupied by the Norwich Crag. The Crag loses its markedly red colour, and the abundant fossils indicate somewhat more boreal condi- tions. Whether the whole of the Norwich Crag is newer than any portion of the Red Crag may reasonably be doubted ; indeed, the generally accepted view that the upper part of the Red Crag, which is sometimes termed the Scrobicularia Crag, is equivalent to the lower part of the Norwich Crag, has much evidence in support of it. This ' Proc. Geo!. Soc. iv. 281. ' Reid, ' Pliocene Deposits of Britain,' p. 6. 14
