FROM NORTHWESTERN EUROPE 45 
DISTRIBUTION. The only records of the species are from the central French Jura 
(Jura lédonien). 
OccURRENCE. Nothing is known except that the material supplied by Dr. Enay 
came from a pale coloured marl, as evidenced by the adhering matrix. 
Rhynchonella sp. 
(Pl. 5, figs. 1-2) 
REMARKS. The species has not been named or described as only four specimens 
are known ; these were donated to the author by Dr. D. A. B. Pearson from the 
Callovian of Kozlowagora in Poland. 
Subfamily IVANOVIELLINAE Makridin, 1964 
EMENDED DIAGNOSIS. Small to medium sized rhynchonellids ; strong, sub- 
angular to rounded ribs ; posterior smooth area ; well marked uniplication and 
linguiform extension often well developed ; septalium present ; crura calcarifer. 
STRATIGRAPHICAL RANGE. ?Pliensbachian—middle Oxfordian. 
Genus THURMANNELLA Leidhold 
1920 Septaliphoria (Thurmannella) Leidhold, pp. 357-62. 
1964 Thurmannella Leidhold; Makridin, pp. 143-44. 
19656 Thurmannella Leidhold; Ager, pp. 609-10. 
TYPE SPECIES. The nominal type species is Terebratula Thurmanni Voltz which 
was designated by Makridin. However, this is regarded by the author as a synonym 
of Terebratula obtrita Defrance and is discussed under the latter species. 
EMENDED DIAGNOSIS. Small to medium sized, subpentagonal, rhynchonellids ; 
ventral valve flattened while the brachial is strongly inflated ; 15-22 simple, sub- 
rounded to subangular ribs which do not arise at the umbones so that there is a 
characteristic but variably developed smooth area posteriorly ; well developed 
uniplication ; linguiform extension usually present but variably developed ; beak 
small, suberect and sharp ; pedicle opening present ; crura calcarifer. 
STRATIGRAPHICAL RANGE. Oxfordian—mariae to lower transversarium zones. 
Species. T. acuticosta sp. nov. 
T. obtrita (Defrance) (1828, pp. 161-62). 
DISTRIBUTION. Thurmannella has been recorded from northern France, the 
northern French Jura, the area around Basel and from Yorkshire and Kent. It is 
not recorded from Germany. 
Remarks. A diagnosis only has been given as a full description is given of the 
type species, T. obtvita ; and a generic description would only differ in being broad- 
ened to include T. acuticosta, which differs from T. obtrita in having a very limited 
posterior smooth area, more angular ribs and a more strongly developed uniplication 
in the anterior commissure. 
Thurmannella was first established by Leidhold (1920) as a new subgenus within 
his new genus Septaliphoria. The close relationship thus suggested for Septaliphoria 
and Thurmannella is based on their both possessing a septalium. It would appear 
