FROM NORTHWESTERN EUROPE 13 
GEOGRAPHICAL AND STRATIGRAPHICAL DISTRIBUTION 
Details of the distribution of individual species are given in the systematic part of 
this study but text-figs. 3-5 have been included to summarise the distribution of the 
genera. These figures are based on information obtained from field observations, 
museum collections and literature. It is considered that the distribution is largely 
controlled by facies and substrate, as shown by the occurrence of Septaliphoria and 
Lacunosella. 
Distribution of Lower Volgian 
rhynchonellid genera 
Fic. 5. Ac=Acanthorhynchia ; La=Lacunosella ; Mo=Monticlarella ; Rh=Rhynchonella ; 
To=Torquirhynchia. 
