A HISTORY OF SUFFOLK specimens. Numerous dermal plates from the Coralline Crag of Orford and Gedgrave, as well as from the nodule bed of the Red Crag, are indistinguishable from those of the living thornback skate {Raia clavata), while a single tooth from the Coralline Crag of Gedgrave has been assigned to the common skate {R. batis). Other dermal plates, from the Red Crag at Boyton and the Coralline Crag at Gedgrave, are regarded by Mr. Newton as indicating a third (perhaps generically distinct) kind of ray. Finally, a small tooth in the British Museum from the nodule bed of the Red Crag of the county indicates a species of monk-fish [Squatind). A second tooth of similar type has been obtained at Little Bealings, and there is a third in the Museum at York, also from the Red Crag. Allusion has already been made to the ' derived ' vertebrate fossils of Suffolk, or those which are definitely known to have been washed out of older formations. These may now be mentioned somewhat more fully. In 1856 Sir R. Owen' described a mammalian tooth from the Red Crag of the county, which he regarded as referable to that primitive group of Carnivora of which the Eocene genera Pterodon and Hycenodon are well known representatives. Although the specimen cannot now be found it is probable that the determination is correct, and that the tooth originally came from the London Clay. That formation is certainly the horizon whence was derived part of a skull of the Eocene mammal Hyracotherium leporinum obtained from the Red Crag of the county and described by Sir R. Owen.^ The genus and species in question, it may be observed, were first described from the London Clay of Kent, and form one of the ancestral types of the horse line. Teeth of a much larger size from the Red Crag of the county, some of which are pre- served in the Museum at Ipswich and others in the Museum of Practical Geology, belong to Coryphodon eocanus, another primitive odd-toed mammal typically from the London Clay of Essex. An imperfect skull in the Museum of the Royal College of Surgeons, said to be from the Red Crag of the county, has been described by Sir W. H. Flower,' and provisionally assigned to the genus Xiphodon, under the name of X. platy- ceps, of which it forms the type. As the teeth are wanting the genus to which this curious specimen belongs cannot be definitely determined. Mr. Newton observes that although its exact age is uncertain, yet it approximates most nearly in general appearance to the so-called box- stones of the Suffolk Crag. The only reptilian remains recorded from the Crag of the county appear to be the skulls of turtles, which have evidently been washed out of the London Clay, and doubtless belong to the forms characteristic of that deposit, such as species of Argillochelys and Lytoloma. Fish palates and teeth, likewise mainly of Lower Eocene types, are far from uncommon in the nodule bed of the Red Crag. Among them ' ^imrt. Jcurn. Geol. Sk. xii. 227. * Geol. Mag. (i) ii. 339. ' Proc. Zool. Sx. 1876, p. 3. 44
