FROM NORTHWESTERN EUROPE 41 
Family RHYNCHONELLIDAE Gray, 1848 
Subfamily RHYNCHONELLINAE Gray, 1848 
Genus RHYNCHONELLA Fischer, 1809 
1809 Rhynchonella Fischer: 35. 
1918 Rhynchonella Fischer: Buckman, 57. 
1920 Eurhynchonella Leidhold: 352. 
1932 Rhynchonella Fischer; Wisniewska: 13. 
1957 Rhynchonella Fischer; Ager: I-15. 
1960 Rhynchonella Fischer, Makridin: 252. 
1964 Rhynchonella Fischer; Makridin: 111-13. 
1965b Rhynchonella Fischer; Ager: H6tro. 
REMARKS. It is not proposed to revise the generic description as the type species, 
R. loxiae, does not occur in western Europe and within this area the genus is only 
represented by rare and very variable “species”. R. loxiae has recently been 
described and figured by Ager (1957) and Makridin (1964). 
In Britain, there are only two described Jurassic “‘species’’ and very little 
material which can be referred to Rhynchonella s.s. The two species are R. port- 
landica Blake and R. subvariabilis Davidson ; the type of the former was collected 
from the Lower Portland Sand of “‘ Black Ven ”’ Portland, and of the latter from the 
Kimmeridge Clay of Potterne, Wilts. Most of the material referable to Rhynchonella 
has been obtained from the “ RAynchonella Marls”’ and various horizons in the 
Portland Sand exposed on the Dorset coast. Apart from this, there are two speci- 
mens from the Lydite Bed of Long Crendon, Buckinghamshire, and six specimens 
from the Kimmeridgian Boulder Beds of Sutherland. Material from these horizons 
is very scarce and the author is indebted to the curators of the Geological Museum, 
Oxford, the Sedgewick Museum, Cambridge, and the B.M.(N.H.), for allowing him 
to use the specimens in their collections. 
An interesting series of specimens collected by Prof. M. R. House from the Upper 
Blackmore Beds, Portland, is figured on plate 4. As these were collected from the 
same horizon and locality, it can be reasonably assumed that they represent a single 
variable species. The variation ranges, however, between end-members, which, if 
they occurred separately and without intermediate forms, would undoubtedly be 
referred to R. portlandica and R. subvariabilis. This suggests that perhaps all the 
British material from this area should be referred to a single species. However, it is 
considered that further stratigraphically accurately located material is needed before 
the full range and variation can be determined ; until then it seems pointless to try 
and define taxonomic groups within this plexus of forms which is at present repre- 
sented by less than thirty specimens, of which few are complete. It is interesting 
to note that Blake (1880) in proposing his species R. portlandica, commented, 
“One can scarcely feel quite certain whether this is a distinct species from R. 
subvariabilis ”’. 
Specimens were collected by the author from the Boulder Beds of Sutherland, 
and appear to be the first record of the genus from that area. Again, as with the 
material from the Dorset coast, it does not seem helpful to propose further taxa 
until more specimens are available. 
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