PALAEONTOLOGY specific identification is a matter of difficulty. The earliest name for teeth of this type is Balt^nodon physaloides^ given by Sir R. Owen in 1846, and typified by a Red Crag specimen. It has been considered that other equally large Suffolk Crag teeth belong to the Belgian whale described as Eucetus amblyodon. Teeth of smaller spermwhale-like cetaceans from the Red Crag nodule bed of the county have been tentatively assigned to the continental forms described under the names of Physeterula dubusii, Physodon grandis, P. fustformis, Hoplocetus crassidens, H. borgerhoutensis, and H. curvidens. If an Argentine Pliocene skull be rightly assigned to it, Physodon differs from the modern sperm-whale in having a full series of teeth in the upper as well as in the lower jaw. The occurrence of a whale closely allied to the existing bottle-nose in the Red Crag was made known by the present writer in the following words : ' Hyperoodon is represented by a very perfect right periotic in the Ipswich Museum. This specimen, which has the accessory ossicle still attached, cannot be distinguished from the corresponding bone of the existing H. rostratus, and evidently indicates the existence either of that or of a closely allied form in the Pliocene ; the occurrence of cervical vertebra of a member of this genus in the Antwerp Crag has been recorded by Professor Van Beneden.' Since it is practically certain that the Crag bot-tle-nosed whale is distinct from the existing species it may be appropriately named Hyperoodon taylori, after the late Dr. J. E. Taylor, some time curator of the Ipswich Museum. Beaked whales, as already said, are very numerously represented by their beaks, or rostra, which in the living species are characterized by their ivory-like appearance and hardness. One type has been referred to a supposed extinct genus, Choneziphius, of which it has been thought that there are three representatives in the Red Crag, namely C planirostris, C. planus and C packardi. Apparently Choneziphius is not generically distinct from the existing beaked whale commonly known as Ziphius, and since the latter term is barred by previous usage in another sense, the former name is entitled to stand for the genus. Of the beaked whales belonging to the same genus as the existing Mesoplodon videns (which occasionally visits the British shores) a large number of species have been named on the evidence of Crag specimens, but it is probable that some at least of these are merely nominal. The list is as follows, viz. Mesoplo- don longirostris, M. tenuirosfris, M. angustus, M. angulatus, M. compressus, M.Jloris and M. scaphoides, in addition to others which are obviously synonyms. It may be added that one specimen of the periotic bone of a member of this genus is known from the Red Crag nodule bed, pre- served in the Museum of Practical Geology. A totally extinct family of cetaceans, the shark-toothed dolphins, in which the hinder teeth are serrated and double-rooted, is represented by isolated teeth from the nodule bed of the Red Crag of the county. Some of these rare and curious teeth are in the Museum at Ipswich, and others at York. They not improbably belong to the species from the Antwerp Crag described as Squalodon antwerpiensis . I 41 6
