616 REPORT— 1902. 



discussion is not specially related to the Devonian forms, but has the elongate shape 

 characteristic of the genera of the Carboniferous and Permian periods. The 

 Acanthodian fragment compared with the Devonian Cheirolepis (which is not an 

 Acanthodian) is too imperfect for consideration. The so-called scales of the 

 Devonian Gltjptolepis, or an allied genus, evidently belong to the large Rhizodont 

 already mentioned, and closely resemble the scales of the Lower Carboniferous 

 Rhizodzcs itself. The Australian fish, however, does not belong to the latter 

 genus : it has teeth round in transverse section. 



The most interesting of all the genera represented in the collection is one 

 rightly recognised by M'Coy as an Elasmobranch allied to the Carboniferous 

 Gyracantkus. It is named Gyracanthides, and is a round-bodied Acanthodian 

 fish, apparently toothless, with the comparatively small and spinous pelvic fins 

 advanced far forwards, as in Acajithodes. Its dorsal fina have not been observed, 

 but its small anal fin is armed with a spine. 



There is also evidence of a small Dipnoan fish with teeth and scales like 

 those of the Carboniferous aod Permian Sagenodus. The typically Carboniferous 

 Palaeoniscidae in the collection are related to Elonichthys. 



There is thus no abnormal mingling of genera in the Early Palfeozoic fish 

 fauna from the Broken River, Victoria. It is a typical Carboniferous assemblage 

 without any extraneous elements. 



8. A Summary of the Principal Changes in South-east England during 

 Pliocene and more Recent Times. By Horace Woollaston Monckton, 

 F.L.S., F.G.S. 



(a) Period of depressio7i iyi South-east Enyland. 



1. Deposition of the bed from which the Box Stones came. 



2. The Lenham Beds. Sea 40 fathoms, extends to Guildford, shells not rolled 

 level 1,000 feet lower than now (Diestian). 



(6) Elevation in South-east England, but depression continues over estuary 



of Shine, 



3. Gravel with large flints of Upper Hale, Aldershot, and the Pebble Gravel 

 ' "Westleton ' of the Chilterns. 



4. Coralline Crag, submarine banks in rather shallow water ; climate that of 

 South Europe. 



6. Red Crag of Walton and Scaldisian of Belgium ; seashore deposits, climate 

 rather warmer than now. 



The beds with Corbula gibba (Poederlian) complete Belgian series, and that 

 country becomes dry land. 



0. Red Crag of Bentley, Newbourn, Butley, seashore deposits. The Amstelian 

 of Holland. Climate colder. 



(e) The depression of the estuary of the Rhine extends to South-east England. 



7. Norwich Crag deposited in sea-water of wide estuary. Chillesford Clay, 

 shells not rolled or water-worn, level lower than now. 



8. Weybourne (Jrag and Bure Valley Beds, depression extending and conse- 

 quent introduction of Tellina balthica. 



(d) Period of great and extensive elevation. 



9. Cromer Forest Bed, level and climate as now. 



10. Leda Myalis Bed, marine with oyster-beds, shells in position of life. 

 Slight local depression. 



11. The Chobham Ridges Gravel and the Plateau Gravels around Reading 

 over 300 feet O.D. come in here. 



12. Arctic Freshwater Bed, flood loam with Succinea. 



