Page:VCH Norfolk 1.djvu/66

 A HISTORY OF NORFOLK deer known as Cervus giganteus carnutorutn. To others, again, the names C suttonensis and C. falconeri have been applied, but their affinities are very doubtful. The horse teeth from the Norwich Crag all belong to the extinct Equus stenonis. Somewhat curiously, no remains of rhinoceros have been recorded from these deposits. Teeth of mastodons, or primi- tive elephants, belonging to the species known as Mastodon arvernensis are, however, by no means uncommon in the Norwich Crag ; where molars of a true elephant, Elephas antiquus, are likewise met with. The molar teeth of mastodons, it may be observed, diffisr from those of modern elephants by their much simpler structure ; their crowns carrying low transverse ridges, sometimes broken up into cones, separated from one another by open valleys, instead of tall and thin plates with the inter- vening spaces completely filled up. The Forest Bed beaver {Trogon- therium cuvieri) extends down to the Norwich Crag, as does the Crag variety of the common field vole [Microtus agrestis wtermedius). The only specifically determined remains of cetaceans found in these deposits within the limits of the county appear to belong to the extinct Crag black-fish {Globicephalus uncidens) and the common dolphin (Delphinus delphis) . Remains of birds and reptiles are unknown, but a considerable number of those of fishes have been obtained, many of which are common to both the Norwich and the Weybourn Crags. Teeth from Bramerton have been assigned conditionally to the existing genus Ceratophrys, while bones of the above-mentioned Platax woodwardi are by no means uncommon. Other remains have been assigned to the cod {Gadus morrhua), an extinct species (G. pseudaglejinus) allied to the haddock, the pollack (G. pollachius), a sturgeon [Acipenser), and the tope shark [Galeus cams), the last-named species being known by teeth from the Weybourn Crag of East Runton. At Thorpe has been obtained a single tooth of a comb-toothed shark {Notidanus) . Dermal plates of the thornback skate [Raia clavata) occur in the Norwich Crag, and teeth of the same species in the Weybourn Crag of East Runton ; and an extinct ray {Rhinoptera woodwardi) is also represented in the Norwich Crag. Two bivalve shells very characteristic of the Norwich Crag at Bramerton — the great collecting place — are Tellina obliqua and Nucula cobboldia. The uppermost or Chillesford beds at this locality show a more decidedly northern type of molluscs than do the underlying fluvio- marine beds, the commoner species being the bivalves Astarte borealis^ A. compressa, Corbula striata, Cyprina islandica, Leda oblongoides, Lucina borealis, and the univalve (whelk) Baccinum undatum tenerum. In addition to the above, the lower beds contain the bivalves Nucula cobboldia, 'Tellina obliqua, T. lata, T. pretenuis, Cardium edule (cockle), Mytilus edulis (mussel), Mactra ovalis, M. subtruncata, Scrobicularia plana. My a arenaria (gaper), and the univalves Littorina littorea (periwinkle), Melampus pyramidalis. Purpura lapillus (banded whelk), Trophon scalariformis, T. antiquus (red whelk), Turritella terebra, Cerithium tricinctum, Scalaria 36