A HISTORY OF SUSSEX belongs to the family Chirocentridce, now represented only by the Indian dorab ; a second species of the same genus, P. mantelli, has been named on the evidence of a Lewes specimen in the British Museum. A lower jaw in the British Museum from the Lower Chalk of Hailing has been provisionally assigned to P. gaultinus, typically from the Gault of Kent. To the same family belongs Ichthyodectes tninor, a fish described on the evidence of a lower jaw from the Sussex Chalk in the British Museum ; other species of the same genus occur in the Chalk of the neighbouring counties. Scales from Lewes have been made the type of Cladocyclus kwesiensis, a species of another Cretaceous genus of the same family. Possibly to this family should be assigned T'omognathus mordax of Dixon, a genus and species described on specimens from the Chalk of the south- east of England, which may have come from Sussex ; other specimens have been found at Amberley, Clayton and Southeram. Ctenothrissa radians^ one of three species of a Cretaceous genus typifying an extinct family closely allied to the herrings, was named by Agassiz (as Betyx) from Lewes specimens, the species also occurring in the Lower Chalk of Clayton and Southeram. Aulolepis typus^ the sole member of its genus, is another member of the same family named from Lewes fossils, and distinguished from the type genus by its smooth- edged scales. Coming to the extinct family Dercetidce, which is allied both to the herrings and salmonoids, we have Leptotrachelus elongatus typified from the Lewes Chalk, the specimens from which were originally described by Agassiz as Dercetis. To an allied family belongs E?ichodus kwesiensis, first described by Mantell as a fossil pike (Esox) ; a second species of the same genus, typically from Kent, has been recently described by Dr. Smith Woodward ^ as E. pulchellus, specimens from Lewes and Southeram being in the British Museum collection. Hake eupterygius, typified by a specimen in the Brighton Museum from Southeram described by Dixon as Pomognathus, is another member of the same family. The same is the case with Cimolichthys lewesie?isis, of which the large spear-like teeth were long incorrectly known by the name of Saurodon. With Acrognathus hoops, typically from Lewes, we come to the scopeloid fishes (Scopelida:) ; the only other known species of the genus is from the Chalk of the Lebanon. Another scopeloid is Apateodus striatus, perhaps identical with the Saurocephalus striatus of Agassiz, and typified by a skull from Lewes ; the two other species of the genus are from the Cretaceous of Kent. Of especial interest is the occurrence of a fossil eel (Urenchelys anglica), known by a head from Lewes in the Brighton Museum, in the Sussex Chalk, since fish of this group are very scarce in the Secondary strata. The other two representatives of the same genus are from the Chalk of the Lebanon. Among the spiny-finned bony fishes the family Berychidce is ' Op. cit. p. 194. 34