256 BRITISH AVONIAN CONODONT FAUNAS 
Fa] 
PEL H 
z 
< 
AVONI 
20 40 60 
Abundance factor- Lota! no. of specimens 
Total weight of sample 
Total weight of 
sample in 
kilograms 
Fic. 69. Lithological section of the upper beds of the Dibunophyllum Zone in the Avon 
Gorge showing the abundance factor of conodonts in each sample dissolved in acetic 
acid. Samples D 23—D 27 were collected from south of Bridge Valley Road (ST 564736). 
