46 JURASSIC RHYNCHONELLIDS 
that Thurmannella was not officially elevated to generic rank until Makridin did so 
in 1964 ; it is also described as a genus in the Anglo-American “‘ Treatise ’’ and the 
author would certainly agree with its separation from Septaliphoria. 
Thurmannella obtrita (Defrance) 
(Pl. 5, figs. 7-9, text-fig. 19) 
1828 Tevebratula obtrita Defrance: 161-62. 
1833 Tervebratula Thurmanni Voltz; Thirria: 172, 179. 
1842 Terebratula Thurmanni Voltz; Boyé: 17, pl. 2, fig. 17. 
1859 Tevebratula Thurmanni Voltz; Oppel: 608. 
1861 Tevebvatula Thurmanni Etallon: 291, pl. 13, fig. 6. 
1865 Tevebratula Thurmanni Ogérien: 656, 661, text-figs. 294-2096. 
1871 Tevebratula Thurmanni Voltz; Quenstedt: go-91, pl. 38, figs. 83-87. 
1882 Rhynchonella Thurmanni (Voltz); Haas and Petri: 238-240, pl. 7, figs. 14-17. 
1884 Rhynchonella obtrita (Defrance); Deslongchamps: 337, pl. 38, figs. 1-3. 
1889 Rhynchonella obtrita (Defrance); Haas; 12-13. 
1897 Rhynchonella Thurmanni (Voltz); Loriol: 143-46. 
1900 Rhynchonella Thurmanni (Voltz); Loriol: 135, pl. 6, fig. 53. 
1901 Rhynchonella Thurmanni (Voltz); Loriol: 112, pl. 6, figs. 17-19. 
1904 Rhynchonella Thurmanni (Voltz); Loriol: 283. 
1917 Rhynchonella Thurmanni (Voltz); Rollier: 154-56. 
1917 Rhynchonella silicola Rollier: 155-56. 
1918 Rhynchonelloidea thurmanni (Voltz); Buckman: 38. 
1920 Septaliphoria (Thurmannella) Thurmanni (Voltz); Leidhold: 363-65, pl. 5, fig. 6, pl. 6, 
figs. 10-18. 
1920 Septaliphoria (Thurmannella) obtrita (Defrance) ; Leidhold: 362-65, pl. 5, fig. 5, pl. 6, figs. 
I-9. 
1964 ?Thurmannella thurmanni (Voltz); Makridin: 135, pl. 6, fig. 53. 
EMENDED bDIAGNosIs. As for genus, except that 7. obtvita always has a well 
developed smooth area posteriorly. 
STRATIGRAPHICAL RANGE. Lower Oxfordian—mariae to lower transversarium 
zones. 
TYPE SPECIMEN. In view of the great confusion in the literature, it has been 
decided that it is necessary to erect a neotype in order to fix the species. The 
specimen proposed was obtained from the “ Terrain a Chailles’’ of Pagny-sur- 
Meurse (Meurthe et Moselle). This is the horizon and area of Defrance’s original 
specimens. The specimen is in British Museum (Nat. Hist.) no. BB. 44145. 
DIMENSIONS OF NEOTYPE. Length 1-40 cm, thickness 1:35 cm, width 1-72 cm. 
MATERIAL. 30 specimens from the “ Terrain a Chailles’’, Pagny-sur-Meurse ; 
in British Museum (Nat. Hist.) nos. BB. 45720-749. 8 specimens from the “ Ter- 
rain a Chailles’’, Liesdorf, near Basel ; 100 from the Renggert Marl of Arc-sur- 
Montenot ; 18 specimens from the Renggeri Marl of Epeugney ; 30 specimens from 
the “ ferruginous oolite ’’ of the Verdun area. 
DescripTIon. External characters. The smallest specimens are equally bi- 
convex, have a laterally suboval outline and only a very low uniplication. All these 
features become considerably modified with growth and in adult specimens the 
brachial valve is very much the more inflated and generally the uniplication is very 
