■62 MR. S. S. BTJCKMAN ON [vol. lxxvi, 



2. Jurassic Chronology: I — Lias: Supplement I, West 

 England Strata. By S. S. Buckman, F.Gr.S. (Read 

 January 7th, 1920.) 



Contents. Page 



I. Introduction 62 



II. Faunal Analyses 63 



(a) Methods of Work. 



(b) Faunal Data, with Table I. 



(c) Faunal Notes. 



(cZ) Consideration of Table I, with Tables II- VII. 

 (e) The Gloucester Fauna, especially Schlotlieimia. 

 with Table VIII. 



III. Additional Enquiries S6 



(a) The Hierlatz and Spezia Faunas. 

 (6) Concerning Small and Large Ammonites, with 

 Tables IX & X. 



IV. Emendations and Corrections of the Earlier Paper, with 



Tables XI & XII 96 



V. Summary, with Tables XIII & XIV 98 



VI. Bibliography 101 



I. Introduction. 



My last communication l left many matters unproved, with 

 indications where further research was required. Thi-ee points 

 especially were — 



(1) The presumed faunal repetition of Uptonia ; 



(2) The Gloucestershire sequence between Phricodoceras and bronni 



(Wessexian 1 to 7), of which it was unknown whether the failure 

 of records was due to lack of strata or, as I was rather disposed to 

 think, to lack of exposure ; 

 (3_) The sequence in early Raasayan — -pve-subplanicugta. - 



Information concerning these three points may be gleaned from 

 -two interesting papers published by Mr. L. Richardson 3 while my 

 communication was in the press. With his information it is now 

 proposed to deal by a method of faunal plotting, which will afford 

 good opportunity of testing faunal dissimilarity by faunal analysis, 

 and seeing how the results accord with those of my former paper. 

 They appear to be specially instructive and to show such consider- 

 able possibilities for the application of faunal plotting to wider 

 fields that they seem to deserve record. Hence this communication 

 is offered to the Society. 



The first of Mr. Richardson's papers records the faunas found in 

 a number of cuttings exposing strata which range from Hwiccian 

 • 5, 3 of my paper, to Deiran 4 4 ; while the second, describing an 



1 II, 8, see Bibliography, p. 101. 2 XVIII, 1. 



3 II, 8, p. 264. 4 II, 8, p. 269. 



