2 FOSSIL FISHES OF THE EXGLISH CHALK. 



species from the English Chalk in the British ]Museuni ' Catalogne of Fossil Fishes,' 

 which was completed last year. All these Avritings will be referred to in due 

 course. 



The unique series of Chalk fishes collected by Mr. Henry Willett has been 

 generously presented by him to the Brighton Museum ; but all the other collections 

 mentioned have been eventually acquired by the British Museum. To the latter 

 are now added the fine collections made l)y S. H. Beckles. J. R. Capron, Frederick 

 Harford, and S. J. Hawkins, l)esides smaller contributions from others. The 

 Forbes-Young collection in the Woodwardian Museum, Cambridge, must also be 

 specially mentioned ; and the series of specimens obtained by the Eight Hon. Lord 

 Ashcombe from the Chalk near Dorking, is likewise of importance. 



A large proportion of the fishes in some of these collections are unfortunately 

 not labelled with the exact horizon and locality. The stratigraphical range of the 

 various species and varieties, therefore, cannot yet be fixed so precisely as is 

 desirable. The researches of Dr. Arthur W. Rowe ^ and Mr. G. E. Dibley ^ have 

 contributed much towards our knowledge of the distribution of some forms ; and 

 the wide experience they have gained of the Chalk in the south of England enables 

 them to determine with much probability of correctness the liorizons of many 

 specimens which lack exact labels. The writer is especially indebted to Mr. Dibley 

 for his advice concerning the probable stratigraphical position of the fossils 

 described from inland chalk-pits. Dr. Barrois^ has already expressed his opinion 

 that most of the specimens from the neighbourhood of Lewes described by Mantell 

 and Agassiz, were obtained from the Turonian zones of Tet'ehrotiiJiiitt r/racilis and 

 lUijinchouclhi. Cnc'icri. 



Finally, it must be noted that in these fossil fishes the outer face of the bones 

 and scales is often destroyed by flaking or by some solvent percolating through the 

 chalk. Differences in the degree of external ornamentation need thus to be 

 examined very critically with an experienced eye before they can be relied upon for 

 the discrimination of species or races. 



It is hoped that the fragmentary fossils will l)e rendered more easily 

 comprehensible by the series of restoi-ed sketches in the text, Avhich have been 

 executed under the author's direction by Miss Gr. M. Woodward. 



1 A. W. Kowe, " The Zoues of the White Chalk of the English Coast. Part I.— Kent and 

 Sussex," Proc. Geol. Assoc, vol. xvi, 1900, pp. 289—368. 



2 G. E. Dibley, " Zonal Features of the Chalk Pits in the Rochester, Gravesend, and Croydon 

 Areas," loc. cit., vol. xvi, 1900, pp. 484 — 496. 



■^ C. Barrois, " Recherches sur le terrain cretace superieur de I'Angleterre et de I'lrlande," Mem. 

 Soc. Geol. Nord., vol. i, no. 1, 1876, p. 30. 



