PALEONTOLOGY mains of Halecopsis insignis, a genus and species typically from the Belgian Eocene, occur at Sheppey. A specially interesting Sheppey fish is Bucklandium diluvii, the only member of an extinct genus of cat-fishes {Siluridce), apparently only known by a single specimen in the British Museum. Two other re- markable fishes from the Sheppey Eocene are Rhynchorhinus branchialis and R. major, the sole representatives of a genus of marine eels {Murcenidce) apparently nearly related to Eomyrus of the Belgian Eocene. The tunnies {Scombrida) are represented by Eothynnus salmoneus, a genus and species at present known only by Sheppey specimens ; another ex- tinct genus, with the two species S. nuchalis and S. macropomus, of the same family peculiar to the formation and locality being Scombrinus. From a still older Eocene deposit, the Thanet Sands of Reculvers, are known four teeth of an extinct porbeagle-like shark, Odontaspis rutoti, typified by remains from the Belgian Eocene. Coming to the fauna of the Cretaceous formations of the county we find the list of reptiles from the Chalk by no means large. It in- cludes however two species of gigantic flying saurians, or pterodactyles, assigned to the Cretaceous genus Ornithochirus, under the names of O. compressirostris and O. giganteus. Of both these species the type speci- mens (now in the British Museum) were obtained by Bowerbank from the Lower Chalk of Burham, the well known locality at the foot of the Chalk escarpment at Blue Bell Hill, which has yielded such a number of vertebrate remains. Acanthopholis horridus, an armoured herbivorous dino- saur, apparently allied to Scelidosaurus of the Lias, was named by the late Professor Huxley on the evidence of vertebrae and dermal plates from the Chalk-marl of Folkestone. The great Cretaceous marine lizards known as Mosasaurians (on account of the remains of the type species having been obtained from the valley of the Meuse) are represented in the Kentish Chalk by one tooth from Gravesend and a second from Maid- stone in the collection of the British Museum, but neither has been generically determined. Another group of marine lizards is typified by Dolichosaurus longicollis, a comparatively small reptile described on the evidence of an imperfect skeleton from Burham, and occurring elsewhere in the county at Liddon Spout near Folkestone. Part of the lower jaw of a reptile from the Middle Chalk of Cuxton has been regarded by Mr. E. T. Newton as possibly belonging to the Rhynchocephalia — a group represented at the present day only by the New Zealand tuatera (Sphenodori) . Of the chelonian order (turtles and tortoises) two species are definitely known from the Kentish Chalk. One of these is a marine turtle, probably allied to the huge Chelone hoffmanni of the topmost Cretaceous of Belgium, and represented in the British Museum by re- mains from Dover and Rochester. The second species, Chelone (or Cimoliocbelys) benstedi, is typified by a specimen from Burham, and is also known by remains from Wouldham and perhaps other localities in the county. Possibly certain chelonian remains from the Gault of Folke- 37
