A HISTORY OF KENT species, Thrissopater magnus, based on remains from Hollingbourne ; while in a fourth we have the species Pachyrhizodus basalis and P. dibleyi (Bur- ham and Maidstone) based on Kentish specimens, and likewise examples of the more widely spread P. gardneri (Burham, Cuxton and near Folkestone) and P. subulidens (Bromley, Burham and Hailing). The fish described by Dixon as Pkthodus expansus is typified by a lower dental plate from Mailing, and also occurs at Gravesend and Maid- stone, as well as in the Folkestone Gault ; its serial position is not de- finitely ascertained, but it probably belongs to one of two still existing famihes — the Osteoglossida or the Albiilidce. A second Sussex species of the genus P. oblongus occurs at Dover, while P. pentagon^ from Burham and Dover, is typically Kentish. In the family Chirocentridce the typically American Cretaceous Portheus is represented in the Chalk of the county by P. daviesi, a species named from a Maidstone specimen, and likewise at Hailing by P. gaultinus, typically from the Folkestone Gault. In another genus of the same family the species Ichthyodectes minor has been recorded from Maid- stone and /. elegans from Dover and Hailing, while /. tenuidens has been named from a Burham specimen. To the same family belongs Clado- cyclus lewesiensis, a typically Sussex fish of which remains are known from Burham and Dover. Saurodon intermedius, a member of a genus of the same family occurring typically in the North American Creta- ceous, was named on the evidence of remains from Dover ; and Tomognathus mordax, a Sussex fish which may perhaps be included in the same family, is represented in the Chalk of Kent by remains from Burham, Chatham and Rochester. Three fishes, Ctenothrissa radians, C. microcephala and Aulolepis typus, of which remains occur at Burham, are typically from the Sussex Chalk, and represent an extinct family [Ctenothrissidce] nearly allied to the modern herrings. The first genus takes its name from the fact that the edges of the scales are pectinated, whereas in the second they are smooth. To the allied family Halosauridce (still represented in deep water at the present day by a member of the type genus) belongs Enchelurus anglicus, a species recently described by Dr. Smith Woodward on the evidence of a specimen believed to be Kentish ; the other two members of the genus are respectively from Westphalia and Syria. In the extinct family Dercetidce, allied both to the herrings and salmonoids, we have Lepto- trachelus elongatus, typically a Sussex fish, recorded from the Chalk of Bromley, Charlton and Dover ; while in the Enchodontidce there is Enchodus lewesiensis from Bromley and Burham, and E. pulchellus from an unknown locality in the county, the former being typically a Sussex and the latter a Kentish fish. To the same family belong Hake eupterygius, from Burham, Hailing and Rochester ; Cimolichthys lewesiensis, from Burham, Dover, Hailing and Maidstone ; and Prionolepis atigustus, from Dover — the two latter being typically from Sussex and the third from Cambridgeshire. In the still living family of scopeloids {Scopelidce) are included Apateodus striatus, from Burham, Cuxton and Maidstone, and 40
